Best Practices for Parasite Control in Beef and Dairy Cattle · Goals • Go back to biology of...
102
Best Practices for Parasite Control in Beef and Dairy Cattle Christine B. Navarre, DVM,MS, DACVIM Extension Veterinarian Louisiana State University Agricultural Center Baton Rouge, LA 70803 [email protected]
Best Practices for Parasite Control in Beef and Dairy Cattle · Goals • Go back to biology of nematodes – Will learn from past mistakes in small ruminants – Will use beef cattle
bull Is there a problemndash Goats-absolutelyndash Horses-yesndash Cattle-rising
Anthelmintic Resistance
bull Inevitable with drug usebull Can also come in with animals
ndash BIOSECURITY
Anthelmintic Resistance
bull Is a demonstrated reduction in the efficacy of an anthelmintic against a nematode species ndash Reduction in the kill against a specific worm
species compared to a proven baselinebull It is due to a change in the genetic makeup
of the worm population that allows it to survive the drug
bull ldquoBadrdquo worms
Refugiabull The proportion of the population that is not selected
by drug treatmentndash ldquoIn Refugerdquo from drug
bull Population of worms with susceptible genes ndash Dilutes resistant worms in that populationndash On pasture (main area) + in animal
bull Key component of slowing drug resistance selection
bull ldquoGood wormsrdquo
Parents Selection for Drug Resistance
Res
ista
nt
Next Generation
Res
ista
nt
Drug Treatment
Anthelmintic Resistancebull Resistant alleles initially at very low numbers
(genotypic resistance)bull Selection pressurebull More worms with resistance genesbull Ultimately phenotypic resistance
bull When ivermectin first released it was not 100 effectivendash Resistance genes pre-exist in worm populations (ldquotolerancerdquo)
Genetics Wormsbull Innate resistance
ndash Some worms more resistant than others to certain products-or some products work better against some parasites than others
bull Genetic ldquotruerdquo resistancendash Genetic mutations selected for with drug use
over timebull Change in population balance
ndash Now more pure Cooperia infestations
16
Gastrointestinal Nematode Resistance Across Active Ingredients
bull Typically gastrointestinal nematode resistance to one active ingredient of a chemical family results in resistance to other active ingredients in that same chemical family
bull Within parasite genus or species resistance to multiple chemical families has been observed
bull Resistance is forever
Selection Pressure
bull Level of refugiabull of treatmentsbull Pharmacokinetics of
drugsbull Host parasite
interactionsbull Biology of the parasitebull Very complicated
Are You Confused Yet
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
bull Sheep goats deer exotic ruminantsndash Also growing problem in cattle
ndash Loves winters in the southndash Loves summer in the northndash Somewhere in-between in
the rest bull Hypobiosis
ndash Hates summers in the south etc
bull Type Ibull Type II
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Why me
bull Not a parasitologistbull Live in parasite heavenbull Interest and passion
Goals bull Go back to biology of nematodes
ndash Will learn from past mistakes in small ruminants
ndash Will use beef cattle as template ndash Cover dairy at the end
bull Think through some scenariosbull Leave you Dazed and Confused
Parasite Control Program vs DewormingProgram
bull There is no cookbook deworming programbull Depends on location in USbull Depends on management on individual herd
ndash Cow-calf vs stocker vs feedlotndash Grazing management
bull Rotational grazing bull Permanent vs prepared seedbedbull Total confinement
bull Is there a problemndash Goats-absolutelyndash Horses-yesndash Cattle-rising
Anthelmintic Resistance
bull Inevitable with drug usebull Can also come in with animals
ndash BIOSECURITY
Anthelmintic Resistance
bull Is a demonstrated reduction in the efficacy of an anthelmintic against a nematode species ndash Reduction in the kill against a specific worm
species compared to a proven baselinebull It is due to a change in the genetic makeup
of the worm population that allows it to survive the drug
bull ldquoBadrdquo worms
Refugiabull The proportion of the population that is not selected
by drug treatmentndash ldquoIn Refugerdquo from drug
bull Population of worms with susceptible genes ndash Dilutes resistant worms in that populationndash On pasture (main area) + in animal
bull Key component of slowing drug resistance selection
bull ldquoGood wormsrdquo
Parents Selection for Drug Resistance
Res
ista
nt
Next Generation
Res
ista
nt
Drug Treatment
Anthelmintic Resistancebull Resistant alleles initially at very low numbers
(genotypic resistance)bull Selection pressurebull More worms with resistance genesbull Ultimately phenotypic resistance
bull When ivermectin first released it was not 100 effectivendash Resistance genes pre-exist in worm populations (ldquotolerancerdquo)
Genetics Wormsbull Innate resistance
ndash Some worms more resistant than others to certain products-or some products work better against some parasites than others
bull Genetic ldquotruerdquo resistancendash Genetic mutations selected for with drug use
over timebull Change in population balance
ndash Now more pure Cooperia infestations
16
Gastrointestinal Nematode Resistance Across Active Ingredients
bull Typically gastrointestinal nematode resistance to one active ingredient of a chemical family results in resistance to other active ingredients in that same chemical family
bull Within parasite genus or species resistance to multiple chemical families has been observed
bull Resistance is forever
Selection Pressure
bull Level of refugiabull of treatmentsbull Pharmacokinetics of
drugsbull Host parasite
interactionsbull Biology of the parasitebull Very complicated
Are You Confused Yet
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
bull Sheep goats deer exotic ruminantsndash Also growing problem in cattle
ndash Loves winters in the southndash Loves summer in the northndash Somewhere in-between in
the rest bull Hypobiosis
ndash Hates summers in the south etc
bull Type Ibull Type II
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Goals bull Go back to biology of nematodes
ndash Will learn from past mistakes in small ruminants
ndash Will use beef cattle as template ndash Cover dairy at the end
bull Think through some scenariosbull Leave you Dazed and Confused
Parasite Control Program vs DewormingProgram
bull There is no cookbook deworming programbull Depends on location in USbull Depends on management on individual herd
ndash Cow-calf vs stocker vs feedlotndash Grazing management
bull Rotational grazing bull Permanent vs prepared seedbedbull Total confinement
bull Is there a problemndash Goats-absolutelyndash Horses-yesndash Cattle-rising
Anthelmintic Resistance
bull Inevitable with drug usebull Can also come in with animals
ndash BIOSECURITY
Anthelmintic Resistance
bull Is a demonstrated reduction in the efficacy of an anthelmintic against a nematode species ndash Reduction in the kill against a specific worm
species compared to a proven baselinebull It is due to a change in the genetic makeup
of the worm population that allows it to survive the drug
bull ldquoBadrdquo worms
Refugiabull The proportion of the population that is not selected
by drug treatmentndash ldquoIn Refugerdquo from drug
bull Population of worms with susceptible genes ndash Dilutes resistant worms in that populationndash On pasture (main area) + in animal
bull Key component of slowing drug resistance selection
bull ldquoGood wormsrdquo
Parents Selection for Drug Resistance
Res
ista
nt
Next Generation
Res
ista
nt
Drug Treatment
Anthelmintic Resistancebull Resistant alleles initially at very low numbers
(genotypic resistance)bull Selection pressurebull More worms with resistance genesbull Ultimately phenotypic resistance
bull When ivermectin first released it was not 100 effectivendash Resistance genes pre-exist in worm populations (ldquotolerancerdquo)
Genetics Wormsbull Innate resistance
ndash Some worms more resistant than others to certain products-or some products work better against some parasites than others
bull Genetic ldquotruerdquo resistancendash Genetic mutations selected for with drug use
over timebull Change in population balance
ndash Now more pure Cooperia infestations
16
Gastrointestinal Nematode Resistance Across Active Ingredients
bull Typically gastrointestinal nematode resistance to one active ingredient of a chemical family results in resistance to other active ingredients in that same chemical family
bull Within parasite genus or species resistance to multiple chemical families has been observed
bull Resistance is forever
Selection Pressure
bull Level of refugiabull of treatmentsbull Pharmacokinetics of
drugsbull Host parasite
interactionsbull Biology of the parasitebull Very complicated
Are You Confused Yet
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
bull Sheep goats deer exotic ruminantsndash Also growing problem in cattle
ndash Loves winters in the southndash Loves summer in the northndash Somewhere in-between in
the rest bull Hypobiosis
ndash Hates summers in the south etc
bull Type Ibull Type II
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Parasite Control Program vs DewormingProgram
bull There is no cookbook deworming programbull Depends on location in USbull Depends on management on individual herd
ndash Cow-calf vs stocker vs feedlotndash Grazing management
bull Rotational grazing bull Permanent vs prepared seedbedbull Total confinement
bull Is there a problemndash Goats-absolutelyndash Horses-yesndash Cattle-rising
Anthelmintic Resistance
bull Inevitable with drug usebull Can also come in with animals
ndash BIOSECURITY
Anthelmintic Resistance
bull Is a demonstrated reduction in the efficacy of an anthelmintic against a nematode species ndash Reduction in the kill against a specific worm
species compared to a proven baselinebull It is due to a change in the genetic makeup
of the worm population that allows it to survive the drug
bull ldquoBadrdquo worms
Refugiabull The proportion of the population that is not selected
by drug treatmentndash ldquoIn Refugerdquo from drug
bull Population of worms with susceptible genes ndash Dilutes resistant worms in that populationndash On pasture (main area) + in animal
bull Key component of slowing drug resistance selection
bull ldquoGood wormsrdquo
Parents Selection for Drug Resistance
Res
ista
nt
Next Generation
Res
ista
nt
Drug Treatment
Anthelmintic Resistancebull Resistant alleles initially at very low numbers
(genotypic resistance)bull Selection pressurebull More worms with resistance genesbull Ultimately phenotypic resistance
bull When ivermectin first released it was not 100 effectivendash Resistance genes pre-exist in worm populations (ldquotolerancerdquo)
Genetics Wormsbull Innate resistance
ndash Some worms more resistant than others to certain products-or some products work better against some parasites than others
bull Genetic ldquotruerdquo resistancendash Genetic mutations selected for with drug use
over timebull Change in population balance
ndash Now more pure Cooperia infestations
16
Gastrointestinal Nematode Resistance Across Active Ingredients
bull Typically gastrointestinal nematode resistance to one active ingredient of a chemical family results in resistance to other active ingredients in that same chemical family
bull Within parasite genus or species resistance to multiple chemical families has been observed
bull Resistance is forever
Selection Pressure
bull Level of refugiabull of treatmentsbull Pharmacokinetics of
drugsbull Host parasite
interactionsbull Biology of the parasitebull Very complicated
Are You Confused Yet
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
bull Sheep goats deer exotic ruminantsndash Also growing problem in cattle
ndash Loves winters in the southndash Loves summer in the northndash Somewhere in-between in
the rest bull Hypobiosis
ndash Hates summers in the south etc
bull Type Ibull Type II
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Is there a problemndash Goats-absolutelyndash Horses-yesndash Cattle-rising
Anthelmintic Resistance
bull Inevitable with drug usebull Can also come in with animals
ndash BIOSECURITY
Anthelmintic Resistance
bull Is a demonstrated reduction in the efficacy of an anthelmintic against a nematode species ndash Reduction in the kill against a specific worm
species compared to a proven baselinebull It is due to a change in the genetic makeup
of the worm population that allows it to survive the drug
bull ldquoBadrdquo worms
Refugiabull The proportion of the population that is not selected
by drug treatmentndash ldquoIn Refugerdquo from drug
bull Population of worms with susceptible genes ndash Dilutes resistant worms in that populationndash On pasture (main area) + in animal
bull Key component of slowing drug resistance selection
bull ldquoGood wormsrdquo
Parents Selection for Drug Resistance
Res
ista
nt
Next Generation
Res
ista
nt
Drug Treatment
Anthelmintic Resistancebull Resistant alleles initially at very low numbers
(genotypic resistance)bull Selection pressurebull More worms with resistance genesbull Ultimately phenotypic resistance
bull When ivermectin first released it was not 100 effectivendash Resistance genes pre-exist in worm populations (ldquotolerancerdquo)
Genetics Wormsbull Innate resistance
ndash Some worms more resistant than others to certain products-or some products work better against some parasites than others
bull Genetic ldquotruerdquo resistancendash Genetic mutations selected for with drug use
over timebull Change in population balance
ndash Now more pure Cooperia infestations
16
Gastrointestinal Nematode Resistance Across Active Ingredients
bull Typically gastrointestinal nematode resistance to one active ingredient of a chemical family results in resistance to other active ingredients in that same chemical family
bull Within parasite genus or species resistance to multiple chemical families has been observed
bull Resistance is forever
Selection Pressure
bull Level of refugiabull of treatmentsbull Pharmacokinetics of
drugsbull Host parasite
interactionsbull Biology of the parasitebull Very complicated
Are You Confused Yet
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
bull Sheep goats deer exotic ruminantsndash Also growing problem in cattle
ndash Loves winters in the southndash Loves summer in the northndash Somewhere in-between in
the rest bull Hypobiosis
ndash Hates summers in the south etc
bull Type Ibull Type II
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Is there a problemndash Goats-absolutelyndash Horses-yesndash Cattle-rising
Anthelmintic Resistance
bull Inevitable with drug usebull Can also come in with animals
ndash BIOSECURITY
Anthelmintic Resistance
bull Is a demonstrated reduction in the efficacy of an anthelmintic against a nematode species ndash Reduction in the kill against a specific worm
species compared to a proven baselinebull It is due to a change in the genetic makeup
of the worm population that allows it to survive the drug
bull ldquoBadrdquo worms
Refugiabull The proportion of the population that is not selected
by drug treatmentndash ldquoIn Refugerdquo from drug
bull Population of worms with susceptible genes ndash Dilutes resistant worms in that populationndash On pasture (main area) + in animal
bull Key component of slowing drug resistance selection
bull ldquoGood wormsrdquo
Parents Selection for Drug Resistance
Res
ista
nt
Next Generation
Res
ista
nt
Drug Treatment
Anthelmintic Resistancebull Resistant alleles initially at very low numbers
(genotypic resistance)bull Selection pressurebull More worms with resistance genesbull Ultimately phenotypic resistance
bull When ivermectin first released it was not 100 effectivendash Resistance genes pre-exist in worm populations (ldquotolerancerdquo)
Genetics Wormsbull Innate resistance
ndash Some worms more resistant than others to certain products-or some products work better against some parasites than others
bull Genetic ldquotruerdquo resistancendash Genetic mutations selected for with drug use
over timebull Change in population balance
ndash Now more pure Cooperia infestations
16
Gastrointestinal Nematode Resistance Across Active Ingredients
bull Typically gastrointestinal nematode resistance to one active ingredient of a chemical family results in resistance to other active ingredients in that same chemical family
bull Within parasite genus or species resistance to multiple chemical families has been observed
bull Resistance is forever
Selection Pressure
bull Level of refugiabull of treatmentsbull Pharmacokinetics of
drugsbull Host parasite
interactionsbull Biology of the parasitebull Very complicated
Are You Confused Yet
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
bull Sheep goats deer exotic ruminantsndash Also growing problem in cattle
ndash Loves winters in the southndash Loves summer in the northndash Somewhere in-between in
the rest bull Hypobiosis
ndash Hates summers in the south etc
bull Type Ibull Type II
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
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Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
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Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
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Day 108
Day 108
Day 108
Life Cycle
httpwwwpetaliacomautemplatesStoryTemplate
Parasite Resistance in Livestock
bull Is there a problemndash Goats-absolutelyndash Horses-yesndash Cattle-rising
Anthelmintic Resistance
bull Inevitable with drug usebull Can also come in with animals
ndash BIOSECURITY
Anthelmintic Resistance
bull Is a demonstrated reduction in the efficacy of an anthelmintic against a nematode species ndash Reduction in the kill against a specific worm
species compared to a proven baselinebull It is due to a change in the genetic makeup
of the worm population that allows it to survive the drug
bull ldquoBadrdquo worms
Refugiabull The proportion of the population that is not selected
by drug treatmentndash ldquoIn Refugerdquo from drug
bull Population of worms with susceptible genes ndash Dilutes resistant worms in that populationndash On pasture (main area) + in animal
bull Key component of slowing drug resistance selection
bull ldquoGood wormsrdquo
Parents Selection for Drug Resistance
Res
ista
nt
Next Generation
Res
ista
nt
Drug Treatment
Anthelmintic Resistancebull Resistant alleles initially at very low numbers
(genotypic resistance)bull Selection pressurebull More worms with resistance genesbull Ultimately phenotypic resistance
bull When ivermectin first released it was not 100 effectivendash Resistance genes pre-exist in worm populations (ldquotolerancerdquo)
Genetics Wormsbull Innate resistance
ndash Some worms more resistant than others to certain products-or some products work better against some parasites than others
bull Genetic ldquotruerdquo resistancendash Genetic mutations selected for with drug use
over timebull Change in population balance
ndash Now more pure Cooperia infestations
16
Gastrointestinal Nematode Resistance Across Active Ingredients
bull Typically gastrointestinal nematode resistance to one active ingredient of a chemical family results in resistance to other active ingredients in that same chemical family
bull Within parasite genus or species resistance to multiple chemical families has been observed
bull Resistance is forever
Selection Pressure
bull Level of refugiabull of treatmentsbull Pharmacokinetics of
drugsbull Host parasite
interactionsbull Biology of the parasitebull Very complicated
Are You Confused Yet
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
bull Sheep goats deer exotic ruminantsndash Also growing problem in cattle
ndash Loves winters in the southndash Loves summer in the northndash Somewhere in-between in
the rest bull Hypobiosis
ndash Hates summers in the south etc
bull Type Ibull Type II
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Parasite Resistance in Livestock
bull Is there a problemndash Goats-absolutelyndash Horses-yesndash Cattle-rising
Anthelmintic Resistance
bull Inevitable with drug usebull Can also come in with animals
ndash BIOSECURITY
Anthelmintic Resistance
bull Is a demonstrated reduction in the efficacy of an anthelmintic against a nematode species ndash Reduction in the kill against a specific worm
species compared to a proven baselinebull It is due to a change in the genetic makeup
of the worm population that allows it to survive the drug
bull ldquoBadrdquo worms
Refugiabull The proportion of the population that is not selected
by drug treatmentndash ldquoIn Refugerdquo from drug
bull Population of worms with susceptible genes ndash Dilutes resistant worms in that populationndash On pasture (main area) + in animal
bull Key component of slowing drug resistance selection
bull ldquoGood wormsrdquo
Parents Selection for Drug Resistance
Res
ista
nt
Next Generation
Res
ista
nt
Drug Treatment
Anthelmintic Resistancebull Resistant alleles initially at very low numbers
(genotypic resistance)bull Selection pressurebull More worms with resistance genesbull Ultimately phenotypic resistance
bull When ivermectin first released it was not 100 effectivendash Resistance genes pre-exist in worm populations (ldquotolerancerdquo)
Genetics Wormsbull Innate resistance
ndash Some worms more resistant than others to certain products-or some products work better against some parasites than others
bull Genetic ldquotruerdquo resistancendash Genetic mutations selected for with drug use
over timebull Change in population balance
ndash Now more pure Cooperia infestations
16
Gastrointestinal Nematode Resistance Across Active Ingredients
bull Typically gastrointestinal nematode resistance to one active ingredient of a chemical family results in resistance to other active ingredients in that same chemical family
bull Within parasite genus or species resistance to multiple chemical families has been observed
bull Resistance is forever
Selection Pressure
bull Level of refugiabull of treatmentsbull Pharmacokinetics of
drugsbull Host parasite
interactionsbull Biology of the parasitebull Very complicated
Are You Confused Yet
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
bull Sheep goats deer exotic ruminantsndash Also growing problem in cattle
ndash Loves winters in the southndash Loves summer in the northndash Somewhere in-between in
the rest bull Hypobiosis
ndash Hates summers in the south etc
bull Type Ibull Type II
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Anthelmintic Resistance
bull Inevitable with drug usebull Can also come in with animals
ndash BIOSECURITY
Anthelmintic Resistance
bull Is a demonstrated reduction in the efficacy of an anthelmintic against a nematode species ndash Reduction in the kill against a specific worm
species compared to a proven baselinebull It is due to a change in the genetic makeup
of the worm population that allows it to survive the drug
bull ldquoBadrdquo worms
Refugiabull The proportion of the population that is not selected
by drug treatmentndash ldquoIn Refugerdquo from drug
bull Population of worms with susceptible genes ndash Dilutes resistant worms in that populationndash On pasture (main area) + in animal
bull Key component of slowing drug resistance selection
bull ldquoGood wormsrdquo
Parents Selection for Drug Resistance
Res
ista
nt
Next Generation
Res
ista
nt
Drug Treatment
Anthelmintic Resistancebull Resistant alleles initially at very low numbers
(genotypic resistance)bull Selection pressurebull More worms with resistance genesbull Ultimately phenotypic resistance
bull When ivermectin first released it was not 100 effectivendash Resistance genes pre-exist in worm populations (ldquotolerancerdquo)
Genetics Wormsbull Innate resistance
ndash Some worms more resistant than others to certain products-or some products work better against some parasites than others
bull Genetic ldquotruerdquo resistancendash Genetic mutations selected for with drug use
over timebull Change in population balance
ndash Now more pure Cooperia infestations
16
Gastrointestinal Nematode Resistance Across Active Ingredients
bull Typically gastrointestinal nematode resistance to one active ingredient of a chemical family results in resistance to other active ingredients in that same chemical family
bull Within parasite genus or species resistance to multiple chemical families has been observed
bull Resistance is forever
Selection Pressure
bull Level of refugiabull of treatmentsbull Pharmacokinetics of
drugsbull Host parasite
interactionsbull Biology of the parasitebull Very complicated
Are You Confused Yet
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
bull Sheep goats deer exotic ruminantsndash Also growing problem in cattle
ndash Loves winters in the southndash Loves summer in the northndash Somewhere in-between in
the rest bull Hypobiosis
ndash Hates summers in the south etc
bull Type Ibull Type II
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Anthelmintic Resistance
bull Is a demonstrated reduction in the efficacy of an anthelmintic against a nematode species ndash Reduction in the kill against a specific worm
species compared to a proven baselinebull It is due to a change in the genetic makeup
of the worm population that allows it to survive the drug
bull ldquoBadrdquo worms
Refugiabull The proportion of the population that is not selected
by drug treatmentndash ldquoIn Refugerdquo from drug
bull Population of worms with susceptible genes ndash Dilutes resistant worms in that populationndash On pasture (main area) + in animal
bull Key component of slowing drug resistance selection
bull ldquoGood wormsrdquo
Parents Selection for Drug Resistance
Res
ista
nt
Next Generation
Res
ista
nt
Drug Treatment
Anthelmintic Resistancebull Resistant alleles initially at very low numbers
(genotypic resistance)bull Selection pressurebull More worms with resistance genesbull Ultimately phenotypic resistance
bull When ivermectin first released it was not 100 effectivendash Resistance genes pre-exist in worm populations (ldquotolerancerdquo)
Genetics Wormsbull Innate resistance
ndash Some worms more resistant than others to certain products-or some products work better against some parasites than others
bull Genetic ldquotruerdquo resistancendash Genetic mutations selected for with drug use
over timebull Change in population balance
ndash Now more pure Cooperia infestations
16
Gastrointestinal Nematode Resistance Across Active Ingredients
bull Typically gastrointestinal nematode resistance to one active ingredient of a chemical family results in resistance to other active ingredients in that same chemical family
bull Within parasite genus or species resistance to multiple chemical families has been observed
bull Resistance is forever
Selection Pressure
bull Level of refugiabull of treatmentsbull Pharmacokinetics of
drugsbull Host parasite
interactionsbull Biology of the parasitebull Very complicated
Are You Confused Yet
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
bull Sheep goats deer exotic ruminantsndash Also growing problem in cattle
ndash Loves winters in the southndash Loves summer in the northndash Somewhere in-between in
the rest bull Hypobiosis
ndash Hates summers in the south etc
bull Type Ibull Type II
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Refugiabull The proportion of the population that is not selected
by drug treatmentndash ldquoIn Refugerdquo from drug
bull Population of worms with susceptible genes ndash Dilutes resistant worms in that populationndash On pasture (main area) + in animal
bull Key component of slowing drug resistance selection
bull ldquoGood wormsrdquo
Parents Selection for Drug Resistance
Res
ista
nt
Next Generation
Res
ista
nt
Drug Treatment
Anthelmintic Resistancebull Resistant alleles initially at very low numbers
(genotypic resistance)bull Selection pressurebull More worms with resistance genesbull Ultimately phenotypic resistance
bull When ivermectin first released it was not 100 effectivendash Resistance genes pre-exist in worm populations (ldquotolerancerdquo)
Genetics Wormsbull Innate resistance
ndash Some worms more resistant than others to certain products-or some products work better against some parasites than others
bull Genetic ldquotruerdquo resistancendash Genetic mutations selected for with drug use
over timebull Change in population balance
ndash Now more pure Cooperia infestations
16
Gastrointestinal Nematode Resistance Across Active Ingredients
bull Typically gastrointestinal nematode resistance to one active ingredient of a chemical family results in resistance to other active ingredients in that same chemical family
bull Within parasite genus or species resistance to multiple chemical families has been observed
bull Resistance is forever
Selection Pressure
bull Level of refugiabull of treatmentsbull Pharmacokinetics of
drugsbull Host parasite
interactionsbull Biology of the parasitebull Very complicated
Are You Confused Yet
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
bull Sheep goats deer exotic ruminantsndash Also growing problem in cattle
ndash Loves winters in the southndash Loves summer in the northndash Somewhere in-between in
the rest bull Hypobiosis
ndash Hates summers in the south etc
bull Type Ibull Type II
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Parents Selection for Drug Resistance
Res
ista
nt
Next Generation
Res
ista
nt
Drug Treatment
Anthelmintic Resistancebull Resistant alleles initially at very low numbers
(genotypic resistance)bull Selection pressurebull More worms with resistance genesbull Ultimately phenotypic resistance
bull When ivermectin first released it was not 100 effectivendash Resistance genes pre-exist in worm populations (ldquotolerancerdquo)
Genetics Wormsbull Innate resistance
ndash Some worms more resistant than others to certain products-or some products work better against some parasites than others
bull Genetic ldquotruerdquo resistancendash Genetic mutations selected for with drug use
over timebull Change in population balance
ndash Now more pure Cooperia infestations
16
Gastrointestinal Nematode Resistance Across Active Ingredients
bull Typically gastrointestinal nematode resistance to one active ingredient of a chemical family results in resistance to other active ingredients in that same chemical family
bull Within parasite genus or species resistance to multiple chemical families has been observed
bull Resistance is forever
Selection Pressure
bull Level of refugiabull of treatmentsbull Pharmacokinetics of
drugsbull Host parasite
interactionsbull Biology of the parasitebull Very complicated
Are You Confused Yet
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
bull Sheep goats deer exotic ruminantsndash Also growing problem in cattle
ndash Loves winters in the southndash Loves summer in the northndash Somewhere in-between in
the rest bull Hypobiosis
ndash Hates summers in the south etc
bull Type Ibull Type II
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Anthelmintic Resistancebull Resistant alleles initially at very low numbers
(genotypic resistance)bull Selection pressurebull More worms with resistance genesbull Ultimately phenotypic resistance
bull When ivermectin first released it was not 100 effectivendash Resistance genes pre-exist in worm populations (ldquotolerancerdquo)
Genetics Wormsbull Innate resistance
ndash Some worms more resistant than others to certain products-or some products work better against some parasites than others
bull Genetic ldquotruerdquo resistancendash Genetic mutations selected for with drug use
over timebull Change in population balance
ndash Now more pure Cooperia infestations
16
Gastrointestinal Nematode Resistance Across Active Ingredients
bull Typically gastrointestinal nematode resistance to one active ingredient of a chemical family results in resistance to other active ingredients in that same chemical family
bull Within parasite genus or species resistance to multiple chemical families has been observed
bull Resistance is forever
Selection Pressure
bull Level of refugiabull of treatmentsbull Pharmacokinetics of
drugsbull Host parasite
interactionsbull Biology of the parasitebull Very complicated
Are You Confused Yet
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
bull Sheep goats deer exotic ruminantsndash Also growing problem in cattle
ndash Loves winters in the southndash Loves summer in the northndash Somewhere in-between in
the rest bull Hypobiosis
ndash Hates summers in the south etc
bull Type Ibull Type II
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Genetics Wormsbull Innate resistance
ndash Some worms more resistant than others to certain products-or some products work better against some parasites than others
bull Genetic ldquotruerdquo resistancendash Genetic mutations selected for with drug use
over timebull Change in population balance
ndash Now more pure Cooperia infestations
16
Gastrointestinal Nematode Resistance Across Active Ingredients
bull Typically gastrointestinal nematode resistance to one active ingredient of a chemical family results in resistance to other active ingredients in that same chemical family
bull Within parasite genus or species resistance to multiple chemical families has been observed
bull Resistance is forever
Selection Pressure
bull Level of refugiabull of treatmentsbull Pharmacokinetics of
drugsbull Host parasite
interactionsbull Biology of the parasitebull Very complicated
Are You Confused Yet
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
bull Sheep goats deer exotic ruminantsndash Also growing problem in cattle
ndash Loves winters in the southndash Loves summer in the northndash Somewhere in-between in
the rest bull Hypobiosis
ndash Hates summers in the south etc
bull Type Ibull Type II
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
16
Gastrointestinal Nematode Resistance Across Active Ingredients
bull Typically gastrointestinal nematode resistance to one active ingredient of a chemical family results in resistance to other active ingredients in that same chemical family
bull Within parasite genus or species resistance to multiple chemical families has been observed
bull Resistance is forever
Selection Pressure
bull Level of refugiabull of treatmentsbull Pharmacokinetics of
drugsbull Host parasite
interactionsbull Biology of the parasitebull Very complicated
Are You Confused Yet
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
bull Sheep goats deer exotic ruminantsndash Also growing problem in cattle
ndash Loves winters in the southndash Loves summer in the northndash Somewhere in-between in
the rest bull Hypobiosis
ndash Hates summers in the south etc
bull Type Ibull Type II
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Selection Pressure
bull Level of refugiabull of treatmentsbull Pharmacokinetics of
drugsbull Host parasite
interactionsbull Biology of the parasitebull Very complicated
Are You Confused Yet
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
bull Sheep goats deer exotic ruminantsndash Also growing problem in cattle
ndash Loves winters in the southndash Loves summer in the northndash Somewhere in-between in
the rest bull Hypobiosis
ndash Hates summers in the south etc
bull Type Ibull Type II
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Are You Confused Yet
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
bull Sheep goats deer exotic ruminantsndash Also growing problem in cattle
ndash Loves winters in the southndash Loves summer in the northndash Somewhere in-between in
the rest bull Hypobiosis
ndash Hates summers in the south etc
bull Type Ibull Type II
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
bull Sheep goats deer exotic ruminantsndash Also growing problem in cattle
ndash Loves winters in the southndash Loves summer in the northndash Somewhere in-between in
the rest bull Hypobiosis
ndash Hates summers in the south etc
bull Type Ibull Type II
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
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Day 108
Day 108
Day 108
Day 108
Haemonchus contortus(Barber Pole Worm)
bull Sheep goats deer exotic ruminantsndash Also growing problem in cattle
ndash Loves winters in the southndash Loves summer in the northndash Somewhere in-between in
the rest bull Hypobiosis
ndash Hates summers in the south etc
bull Type Ibull Type II
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Why is H contortus such a problem
bull Very fecund ~ 5000 eggs per dayndash 300 worms 15 million epd per
animalndash 30 goatssheep 1 billion eggs over 3
weeks
So What Happened in Sheep and Goats
bull The Perfect Stormndash Haemonchus contortus
bull Very fecundndash Less than 3 week life cycle
bull Lots of infective larva very quicklybull Many generations over a summer
ndash Long transmission season - southern USbull All year long in some parts
ndash Goats acquire little immunitybull Immunity is slow to develop in sheep
Background to the Problem
bull Age of modern anthelminticsbull Parasitologists (and subsequently veterinarians
in the field) recommended strategies that maximized benefits of treatment
bull Over-reliance on anthelminticsndash Over-use of anthelminticsndash Therapeutic vs prophylacticndash Loss of common sense management-based
approaches
Managing Toward Resistancebull Deworm 6-12X per year
ndash Whether needed or not to keep sheepgoats alive bull Underdosingbull Treat everything and move to ldquosaferdquo pasture
ndash NO REFUGIAbull No pasture rotation
ndash Parasites build up ndash More need for treatmentbull The Boer goat arrived
ndash No biosecurityndash ldquoCondominiums for Haemonchusrdquo DG Pugh
The End Resultbull Multi-drug resistance
is widespread and getting wider in sheep and goats
bull Many farms have worm populations that are resistant to all products currently availablendash 1 in 5 in SE (2008)
Cattle Parasites
bull Ostertagia ostertagindash Most pathogenic parasitic species in cattle
ndash Loves winters in the southndash Loves summer in the northndash Somewhere in-between in
the rest bull Hypobiosis
ndash Hates summers in the south etc
bull Type Ibull Type II
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
So What Happened in Sheep and Goats
bull The Perfect Stormndash Haemonchus contortus
bull Very fecundndash Less than 3 week life cycle
bull Lots of infective larva very quicklybull Many generations over a summer
ndash Long transmission season - southern USbull All year long in some parts
ndash Goats acquire little immunitybull Immunity is slow to develop in sheep
Background to the Problem
bull Age of modern anthelminticsbull Parasitologists (and subsequently veterinarians
in the field) recommended strategies that maximized benefits of treatment
bull Over-reliance on anthelminticsndash Over-use of anthelminticsndash Therapeutic vs prophylacticndash Loss of common sense management-based
approaches
Managing Toward Resistancebull Deworm 6-12X per year
ndash Whether needed or not to keep sheepgoats alive bull Underdosingbull Treat everything and move to ldquosaferdquo pasture
ndash NO REFUGIAbull No pasture rotation
ndash Parasites build up ndash More need for treatmentbull The Boer goat arrived
ndash No biosecurityndash ldquoCondominiums for Haemonchusrdquo DG Pugh
The End Resultbull Multi-drug resistance
is widespread and getting wider in sheep and goats
bull Many farms have worm populations that are resistant to all products currently availablendash 1 in 5 in SE (2008)
Cattle Parasites
bull Ostertagia ostertagindash Most pathogenic parasitic species in cattle
ndash Loves winters in the southndash Loves summer in the northndash Somewhere in-between in
the rest bull Hypobiosis
ndash Hates summers in the south etc
bull Type Ibull Type II
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Background to the Problem
bull Age of modern anthelminticsbull Parasitologists (and subsequently veterinarians
in the field) recommended strategies that maximized benefits of treatment
bull Over-reliance on anthelminticsndash Over-use of anthelminticsndash Therapeutic vs prophylacticndash Loss of common sense management-based
approaches
Managing Toward Resistancebull Deworm 6-12X per year
ndash Whether needed or not to keep sheepgoats alive bull Underdosingbull Treat everything and move to ldquosaferdquo pasture
ndash NO REFUGIAbull No pasture rotation
ndash Parasites build up ndash More need for treatmentbull The Boer goat arrived
ndash No biosecurityndash ldquoCondominiums for Haemonchusrdquo DG Pugh
The End Resultbull Multi-drug resistance
is widespread and getting wider in sheep and goats
bull Many farms have worm populations that are resistant to all products currently availablendash 1 in 5 in SE (2008)
Cattle Parasites
bull Ostertagia ostertagindash Most pathogenic parasitic species in cattle
ndash Loves winters in the southndash Loves summer in the northndash Somewhere in-between in
the rest bull Hypobiosis
ndash Hates summers in the south etc
bull Type Ibull Type II
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Managing Toward Resistancebull Deworm 6-12X per year
ndash Whether needed or not to keep sheepgoats alive bull Underdosingbull Treat everything and move to ldquosaferdquo pasture
ndash NO REFUGIAbull No pasture rotation
ndash Parasites build up ndash More need for treatmentbull The Boer goat arrived
ndash No biosecurityndash ldquoCondominiums for Haemonchusrdquo DG Pugh
The End Resultbull Multi-drug resistance
is widespread and getting wider in sheep and goats
bull Many farms have worm populations that are resistant to all products currently availablendash 1 in 5 in SE (2008)
Cattle Parasites
bull Ostertagia ostertagindash Most pathogenic parasitic species in cattle
ndash Loves winters in the southndash Loves summer in the northndash Somewhere in-between in
the rest bull Hypobiosis
ndash Hates summers in the south etc
bull Type Ibull Type II
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
The End Resultbull Multi-drug resistance
is widespread and getting wider in sheep and goats
bull Many farms have worm populations that are resistant to all products currently availablendash 1 in 5 in SE (2008)
Cattle Parasites
bull Ostertagia ostertagindash Most pathogenic parasitic species in cattle
ndash Loves winters in the southndash Loves summer in the northndash Somewhere in-between in
the rest bull Hypobiosis
ndash Hates summers in the south etc
bull Type Ibull Type II
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Cattle Parasites
bull Ostertagia ostertagindash Most pathogenic parasitic species in cattle
ndash Loves winters in the southndash Loves summer in the northndash Somewhere in-between in
the rest bull Hypobiosis
ndash Hates summers in the south etc
bull Type Ibull Type II
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Cattle Ostertagiabull Cool season parasite
ndash Loves winters in the southndash Loves summer in the northndash Somewhere in-between in
the rest bull Hypobiosis
ndash Hates summers in the south etc
bull Type Ibull Type II
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Cooperia and Haemonchus placeii
bull Immunity develops by about one yearbull Warm season parasites
ndash More of problem in summerbull Rarely cause problems unless in high numbers
ndash Intense grazing systemsndash Same pastures used for young calves year after year
bull Few studies (and old) and usually C oncophora which is considered least pathogenic
bull punctatagtpectinatagtoncophorabull Resistance is a concern with these parasites at this time
ndash Usually C punctatandash Donrsquot know if resistant parasites will be more pathogenicndash Recent study of pure C punctata in feedlot showed significant
decreases in ADG and intake
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Parasites in Cattle
bull Haemonchus contortusndash Increasing reports of this in cattlendash Calves exposed to high levels ndash Pastures with previous goat grazingndash Low immunity-DAIRY CALVES
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Parasite Control Historicalbull Strategic deworming for Ostertagia
ndash When parasites canrsquot survive in environmentndash Most of parasites are in animalndash Deworming + environmental control = best
knockdownndash Prevents Type II diseasendash Knocks down parasites going into tough nutritional
timesbull IS THIS STILL A GOOD RECOMMENDATION
ndash Million dollar question
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
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3699
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512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
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Day 59
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Day 108
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Anthelmintic Resistance in Cattle Parasites
bull USndash Well-documented peer reviewed case reports in
literature are increasingndash Started with high-intensity stocker operations
gt20 yrs use of ivermectin 6-12X per yearndash Two research stations in LA so farndash Many anecdotal reports
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Anthelmintic Resistance in Cattle Parasites
bull Kaplan lab UGAndash Cow calf operations in Georgia
bull Eprinex Dectomax combo SafeguardDectomaxbull ML-resistant Cooperia were present on 5 of the 6
farmsbull One farm also ML-resistant Ostertagia
(FECR=847 90) and Haemonchus(FECR=163 45) Epx and Dect respectively
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
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02
622
512
06
2344
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242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
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37
2903
1923
4708
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554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
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Day 14
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Day 31
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Day 45
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Day 108
Day 108
Anthelmintic Resistance in Cattle Parasites
bull Worldwidendash Name a parasite-dewormer combo and
probably a reportndash Ostertagia rising
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Anthelmintic Resistance in Cattle Parasites
bull Highly effective dewormers availablebull Started relying on anthelmintics for
strategic controlbull Forgot about other methods
ndash Reason we have had cases in stockersbull Paid on gainsbull Use ldquobetterrdquo dewormer more frequently
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Compounding Factorsbull Acquired Immunity
ndash Variablendash Never completendash Some exposure is
goodneeded
bull Agendash Immunity to Ostertagia
takes longerndash Adults never exposed
bull Breedndash Brahman
bull Sexndash Males
bull Nutritionbull Larval inhibitionbull Within breed
ndash Heritability Index = 03
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Treatment failure ne Resistance
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
bull Inadequate dose administeredndash Underestimated weightndash Drug was spilledspit-outndash Calculation errorsndash Suspensions not thoroughly mixedndash Invalid extrapolation of dosendash Treatment not actually given
bull Activity of the drug reducedndash Beyond expiration datendash Stored improperlyndash Genericsndash Very thin animals
bull Reinfection
Non-Resistance ldquoTreatment Failuresrdquo
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Non-Resistance ldquoTreatment Failuresrdquobull Errors in FECRT
ndash Improper or non-quantitative egg counting technique
ndash Re-infectionbull Sampled too late after treatmentbull Variation among species amp
strainsndash Inadequate time for drug to
workbull Sampled too soon after treatment
ndash Wide variation within and between animals
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
What Does All This Mean
bull A diagnosis of parasitism is not indicative of an anthelmintic deficiency but of a management problem
bull Anthelmintics can no longer be thought of as a management tool to be used as needed to improve animal productivity
bull Control must be practiced with an eye to the futurebull Reality = effective long-term control will only be possible if
anthelmintics are used intelligently with prevention of resistance as a goal
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
What about diagnostics
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Fecal Egg Count Reduction Testbull Suspect lack of efficacy if less than 95 reduction in
Fecal Egg Count (FEC)ndash Really for sheep and goats
bull Cattlehorses not validatedbull FEC should start out greater than 100 200 to be valid
ndash Cutoff should be 98ndash Compared to pretreatment counts
bull Each animal is itrsquos own control
ndash Compared to control groupbull Pour-ons and licking behavior
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
FECRT Phenotypic Resistancebull Perhaps not think about resistance as ldquoyesrdquo or
ldquonordquo but as sliding scalendash FECRT wonrsquot detect until 25 genetic resistance
(in sheep and goats)ndash Then itrsquos too late
Cattle FECRT Issuesbull Often low beginning EPG
ndash Account for statistical variabilitybull Fecundity
ndash Cooperia amp Haemonchus more fecundbull EPG higher but less pathogenic worms
ndash Changes with immune status seasonbull Ostertagia Pre-type II infestation
Cattle FECRT Issuesbull Fecal water and volume influence weight
and EPGbull Anthelmintics may temporarily sterilize but
not kill wormsndash Falsely low EPG-miss resistance
bull You can take multiple samples from the same fecal pat and get varying numbersndash Can vary with time of day
FECRT Issuesbull Variation within labbull Method
ndash Sugar with centrifugation is gold standardndash SaltMcMasters and Flotac
bull Not as sensitivendash Standing sugar float
bull Not quantitativebull StatSpin OvaTube SqueezeTest
ndash May be superior to just standing float for recovery of eggs and make centrifugation less messy
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Cattle FECRT Issuesbull Often low beginning EPG
ndash Account for statistical variabilitybull Fecundity
ndash Cooperia amp Haemonchus more fecundbull EPG higher but less pathogenic worms
ndash Changes with immune status seasonbull Ostertagia Pre-type II infestation
Cattle FECRT Issuesbull Fecal water and volume influence weight
and EPGbull Anthelmintics may temporarily sterilize but
not kill wormsndash Falsely low EPG-miss resistance
bull You can take multiple samples from the same fecal pat and get varying numbersndash Can vary with time of day
FECRT Issuesbull Variation within labbull Method
ndash Sugar with centrifugation is gold standardndash SaltMcMasters and Flotac
bull Not as sensitivendash Standing sugar float
bull Not quantitativebull StatSpin OvaTube SqueezeTest
ndash May be superior to just standing float for recovery of eggs and make centrifugation less messy
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
Cattle FECRT Issuesbull Fecal water and volume influence weight
and EPGbull Anthelmintics may temporarily sterilize but
not kill wormsndash Falsely low EPG-miss resistance
bull You can take multiple samples from the same fecal pat and get varying numbersndash Can vary with time of day
FECRT Issuesbull Variation within labbull Method
ndash Sugar with centrifugation is gold standardndash SaltMcMasters and Flotac
bull Not as sensitivendash Standing sugar float
bull Not quantitativebull StatSpin OvaTube SqueezeTest
ndash May be superior to just standing float for recovery of eggs and make centrifugation less messy
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
S + C
C + S
C
S
CON
Day -11
378
3699
3714
3721
4147
Day 0
378
3699
3714
3721
4147
Day 14
02
622
512
06
2344
Day 31
242
3731
3131
113
759
Day 45
388
5276
2857
551
9933
Day 59
854
6217
3721
1057
6357
Day 73
513
1434
956
668
916
Day 87
393
37
2903
1923
4708
Day 108
554
987
1509
1849
3375
Day -11
Day -11
Day -11
Day -11
Day -11
Day 0
Day 0
Day 0
Day 0
Day 0
Day 14
Day 14
Day 14
Day 14
Day 14
Day 31
Day 31
Day 31
Day 31
Day 31
Day 45
Day 45
Day 45
Day 45
Day 45
Day 59
Day 59
Day 59
Day 59
Day 59
Day 73
Day 73
Day 73
Day 73
Day 73
Day 87
Day 87
Day 87
Day 87
Day 87
Day 108
Day 108
Day 108
Day 108
Day 108
FECRT Issuesbull Variation within labbull Method
ndash Sugar with centrifugation is gold standardndash SaltMcMasters and Flotac
bull Not as sensitivendash Standing sugar float
bull Not quantitativebull StatSpin OvaTube SqueezeTest
ndash May be superior to just standing float for recovery of eggs and make centrifugation less messy
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Strongylid Eggsbull Cannot differentiate
HOTC complex eggsndash ldquoThe mother worms cannot even
differentiate the baby eggsrdquoDr Tom Craig TAMU
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Fecal Egg Counts
bull Economics vs diseasewelfarebull Economic threshold (USA)
ndash Cows-20 EPGndash Calves 50-500 EPG
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Other Diagnostics for Evaluating Resistance
bull Coproculturendash Hatch eggs then actually identify and count larvae
bull PCRndash Can give semi-quantitative results as to which eggs are
from which speciesndash Quantitative techniques under investigation
bull Genetic testsndash Have to know mutation probe for each mechanism
bull Pooled fecal tests Flotac phone counting app Etc
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Other Diagnostics for Evaluating Resistance
bull Drenchritereg
ndash Larval development assayndash Validated for H contortus (sheepgoats)
bull Detects genetic resistance at 10ndash Only for drugs effective against larval stagesndash Get ldquotiteredrdquo results larvae identification
bull ldquoTracerrdquo animalsndash To estimate pasture contaminationefficacyndash Expensivetime consumingndash Only definitive test for efficacyresistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
bull TTndash Treat whole herd based on risk keeping refugia in mindndash Goal is to reduce number of treatments to herd of flock
bull Opposite of ldquostrategic dewormingrdquondash More prophylactic based on historical epidemiology
bull TSTndash Only treat those that will benefit mostndash Based on parasite or production indicators
bull Sheep simulation study indicated that live weight may be best indicator
ndash Some studies show it only takes leaving 10 of group untreated to work
bull Likely animal-parasite-age-locale dependent
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
TST of SheepGoatsbull Worms not equally
distributed ndash 8020 Rule
bull Most worms = most anemicndash Haemonchus contortusndash Treat or cull
vs sustainable businessndash Survival of the fittest
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Selective TreatmentFAMACHA
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Five Point Checkcopy
bull Eye back tail jaw nosecoatbull Addresses limitations of FAMACHAbull Helps deal with decision on FAMACHA
score 3s
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Bottom Line-Goats in Louisianabull Purebred (ldquolinerdquo bred) show
goatsndash Do not ever live on grassndash Drylot
bull Commercial goatsndash Crossbred doesndash FAMACHA to select
survivorsndash Purebred bucks for genetics
bull Only on grass during breeding season
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Beef Cattle
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
The Goodbull Haemonchus (sheepgoats)
vs Ostertagia (cattle)ndash Haemonchus very fecund compared to Ostertagia
bull If combined with bad management- quickly get large numbers of resistant parasites
bull (High output good if need refugia)bull Could be bad for stockers under ldquobadrdquo pasture
managementndash CooperiaHaemonchus
bull H placeii most common in calves=longer prepatentperion than H contortus
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
The Goodbull Ostertagia usually doesnrsquot kill
ndash Haemonchus in sheepgoats doesbull Leads to more need for treatment
bull Ostertagia least likely to get resistance ldquobuilduprdquondash Short lived adults-die off quickerndash Less time to produce eggsndash Buildup of resistant parasites will take longer
bull Cows act as vacuum cleaners for Cooperia and Haemonchus
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
The Goodbull There is hope for diagnostics
ndash Drenchritendash Statistical modeling -diagnostics and
epidemiologyndash Genetic tests for worm populations and animals
(SNPs)bull There is hope for increasing refugiabull Because of awareness producers more
likely to listen to us
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
The Badbull Resistant genes already there
ndash No way yet to detectbull No product is immunebull Resistance is forever
ndash Except for levamisolebull Reversion to susceptible in 7 years with no use (sheep)
bull We are less likely in cattle to have something clinical simple effective and chuteside like FAMACHA
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
The Uglybull What we donrsquot know
ndash What role does refugia play in cattlebull Should we continue to recommend strategic deworming
of all cattle at onceraquo Decreases refugia but also decreases the need for as many
future treatments
ndash How exactly should we modify our current recommendations
bull Different types of operations (cow-calf vs stocker)bull Different parts of the countrybull Different times of yearbull Grazing-young before old or vice versa
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
The Uglybull If we want to
selectively treatcull susceptible individuals how do we do thatndash FECndash Body condition
bull Young vs olderbull Sheep and goats
ndash most resistant usually not best growth
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
The Ugly
bull Heritability of FEC is low to moderatebull Correlations of FEC to other production
traitsndash Mixed results
bull Cattle-FEC and weaningyearling weight was 4134
ndash Positive but unfavorable correlation might be due to resilience-ability of host to maintain undepressed production under parasite challenge
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Genetic Markers Animals
bull One gene or multiplebull Same for all parasites or parasite dependent
ndash BRDSbull Animal speciesbreed dependent
ndash Taurus vs indicusbull Genotype x environment interactions
ndash Organic high rainfall arid etc
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
The Uglybull Will we see resistance in Ostertagia
ndash Or better question-when will we seehellipbull Is resistant Cooperia more pathogenic
ndash Will that change expected patternsbull Number of parasites to be pathogenicbull Problems in older animalsbull Changes in seasonal patterns
bull It is a moving targetndash Can we figure our what to do before it changes
again
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Now What
bull Based on what we know and surmise what are best practices for diagnosis and control
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Collect approximately 20 fecal samples (more is better) from group of cattle of similar age at the time of deworming Always take samples from the rectum and place in a plastic bag Remove any excess air and seal the sample Refrigerate if samples will not be performed the same day
bull Perform McMasterrsquos technique for quantitative fecal egg counts If sample is 0 on McMasterrsquos perform a Wisconsin Double Centrifugal Sugar Flotation
bull In 14-21 days collect follow-up fecal samples from the 15 animals with the highest eggs per gram from the previous sampling
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
bull Calculate the fecal egg count reduction for each animalSample 1 EPG ndash Sample 2 EPG X 100 = reduction in eggs per gram
Sample 1 EPG
bull Average the resultsbull Consider turning in pooled fecal samples pre and post
treatment for parasite species identification via coproculture
bull If submitting samples to a commercial lab for fecal egg counts make sure to ask for the above techniques
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
FECRT Summarybull Take as many fecals as possiblebull Pick 15 animals with highest counts-repeat
on same animalsbull Wait at least one month after start of
grazing
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Control in Generalbull Increase immunity
ndash Proteinndash Newer research looking into delaying treatment
to increase immunity and decreasing need for treatment later
ndash Increase growth=increase need for forage=increase intake=increase exposure to larvae=increase immunity early (computer modeling)
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Control in Generalbull Use cows as vacuum cleaners for calves
ndash Also other grazing livestock speciesbull Horses goats
bull Donrsquot buy resistant wormsndash Deworm with multiple classes on arrivalndash Drylot for 24-48 hoursndash Turnout onto contaminated pasture
bull Cull poor doersbull USE HYBRID VIGOR
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Pasture Rotation for Parasite Control
bull Pasture rotation is not necessarily for parasite control
bull Rotate for pasture management amp nutritional management
bull Sometimes itrsquos badndash ldquoBermudagrass was developed to propagate Haemonchusrdquo
Tom Craig TAMU
bull Can help control secondary effects of parasites
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Clean vs Contaminated Pasturebull Cleaner
ndash Environment cleansbull Ostertagia in summerbull Cooperia in winter
ndash Grazed by other speciesndash Stocker pastures grazed by cows (cleaner)
bull Cleanestndash Tilled and plantedndash Used for hay
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Rotation of Dewormersbull Pick the right product for the right time
ndash Inhibited larvandash Fly control benefits
bull Donrsquot just use for fly control
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Use products properlybull Use generics with data to back them upbull Use pour-ons sparinglybull Dose adult cows with dose for heaviest cowbull Dose calves based on actual weight or heaviestbull Donrsquot deworm in feed or mineralbull Store products properly
ndash Not outsidebull Combos
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Keeping Refugiabull Either on pasture in animals or both
ndash If you have a clean pasture you need some ldquodirtyrdquo animalsbull Donrsquot deworm all animals before turnout onto clean pastures
ndash Especially with macrocyclic lactones and other long acting productsndash Most practical with cow-calf pairs
raquo Donrsquot deworm cows 5 years and over-older cows then have refugiaraquo Based on breed and locale
ndash Avoid deworming cows going into summer in South-no Ostertagia refugiandash If you want to have all clean animals (calves stockers replacement
heifers) have ldquodirtyrdquo pasture or non-permanent pasturesbull Avoid keeping replacement heifers that have all been dewormed and then
put on clean pasture for grazingndash They will likely only have resistant parasites in the gutndash If a must treat like new arrivals (combo treat drylot turnout on contaminated
pasture)
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Keeping Refugiabull Targeted selective treatment of calves based
on FECndash Hard sell to producers but best way to keep
Cooperia refugiandash Some initial studies indicate this can be done
with little impact on productionndash Very dependant on situation
bull Stockers from multiple sourcesndash Source of cattle had the most influence on performancendash Overshadowed parasite control differences
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Keeping Refugiabull For replacement heifers where deworming the whole group
may be desirablendash Turn out onto contaminated pasture following deworming
bull Avoid keeping replacement heifers that have all been dewormed and then put on clean pasture for grazing (ex from stocker operation)ndash They will likely have only resistant parasites in the gutndash If unavoidable treat like new herd additions above
bull Avoid using the same pastures for young stock year after yearndash For example donrsquot raise replacement heifers in the same pasture
year after year ndash move the ldquoheifer pasturerdquo around on the ranch
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Keeping Refugiabull For stocker calves where deworming the whole group may
be desirablendash Avoid permanent pastures used only for young stock combined
with long‐acting productsndash This is certain to produce an almost pure anthelmintic resistant
population of parasites over time
bull If long‐acting products are used all stockers should go to feedyards for eventual harvest and pastures should be tilled used for hay or left fallow for several monthsndash Even if you turn out onto contaminated pasture cattle act as
vacuum cleaners and eliminate pasture contamination over timendash Only thing left are resistant parasites in the animalndash Will they prevent development of immunity
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Replace Refugia
bull Some studies show promisendash Sheepndash Cattle
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Pitfallsbull Type II Ostertagiasis
ndash If becomes a problem may have to re-evaluate program
bull Switch to more use of benzimidazoles may lead to resistance in that class
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Alternative Controls
bull Tannins in forage (fresh or haypellets) to decrease egg hatching and infective larvae developmentndash Sericea lespedeza
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Condensed Tannin Containing Plants
bull Sericea lespedeza
ndash Forage that grows relatively well in SE USbull Weed bull Establishment as pasture may fit some operationsbull Hay meal pellets etc may be suited for many other
operations
ndash Has effect on Haemonchusbull Plant extracts
ndash Drench or in pelleted feed
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Copper-oxide Wire Particlesbull Haemonchus onlybull Marketed for use in cattle (Copasure) where copper
deficiency is commonbull Appears to work better in sheep but potentially toxicbull May be worth a try in goats
ndash Selective treatment for individuals (FAMACHA)bull Copper sulfate added to feed is not the same
ndash Does not work
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Worm-trapping Fungibull Duddingtonia flagrans
ndash Feed to animals pass in feces prevent larval development
ndash Must be fed every day for 60 daysndash Works in other species alsondash Bolus being developedndash Affects all worm larvae in fecesndash Feed daily with supplementndash Primary objective is to clean up pasturendash Long term results ( maybe 2-3 years)
httpswwwyoutubecomwatchv=jOwCOLf0IRU
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Vaccinebull Promising for Haemonchus (Barbervax)
ndash Works well in sheep and goatsndash Drawback
bull 3 initial doses bull Protection only lasts 6 weeks
ndash Expensive to produce nowbull Genetically engineered product is under
developmentndash Cost will be acceptable if successful
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Alternative Controlbull Co-grazing with other livestock speciesbull Buy refugiabull Breed selection
ndash Use resistant breeds for crossbreeding bull Hybrid Vigor
bull Other plantsndash Birdsfoot trefoil
bull Vitamin Ebull Immune modulating drugsbull Engineered probiotics Cry5B -protein made naturally by the soil
bacterium Bacillus thuringiensis which is harmless to higher animals but toxic to parasitic worms
bull GMO worms and or GMA animalsbull Integrated control programs
ndash Sounds great BUThellipbull We donrsquot know yet what that actually entails
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
New Productsbull Resistance (~2 years) will outpace new drugs (decades)bull Monepantel (Zolvixreg)
ndash Amino-acetonitrile derivative (AAD)ndash US soon
bull Derquantelndash Spiroindole (SI) ndash Sheep in AustraliaNZ
bull Toxic to horsesndash Not likely to come to US
bull ldquoWorminatorrdquo systemndash New computer based technology for rapid screening of
antiparasitic compoundsbull Looks at motility post treatmentbull Doesnrsquot work for ML well
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Common Situations-Beef
bull Assumptionsndash Early spring calvingndash Fall weaningndash Retaining some
replacementsndash Maybe keeping
stockers
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Common situations-Beefbull Winter-with ryegrass
ndash High protein is goodndash But Ostertagia is happy
bull Pay close attention to deworming replacement heifers young cows and bulls
ndash Overseededdrilled pastures that were recently grazed will likely be contaminated
bull Deworming all is probably ok but not always necessaryndash Prepared seedbed will likely have no refugia
bull Donrsquot deworm all right before turnout bull Graze for a month then deworm all
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Common situations-Beef
bull Deworm in fall for flukesndash Will affect other parasites alsondash Keep on contaminated pasturendash Ivermectin +clorsulon-donrsquot treat allndash If severe problems requiring treatment of all
ages consider albendazolendash Resistance in flukes
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Common Situations-Beefbull Winter-no ryegrass
ndash Poor nutrition combined with permanent pastures during peak Ostertagia time spells potential disaster
bull Especially when combined with cold wet mudndash Decision to deworm again depends on nutrition
BCS diagnostics previous deworming etc bull Spring
ndash Deworm nursing calves based on fecalsndash Deworm replacements and bulls depending on
winter deworming fecal samples
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Common Situations-Beefbull Summer
ndash Deworm nursing calves based on fecal examsndash Fall-born summer stockers
bull Most susceptible age for Cooperia going into peak Cooperiaseason
bull Best to treat with product selection based on diagnostics and based on fecal egg counts
ndash Macrocyclic lactones plus a white dewormer (with levamisole also=best)ndash Need more research
raquo All at onceraquo In series
raquo What order
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Common Situations-Dairybull Calves in hutches-little
riskbull Weaned from hutches-BIG
RISKndash The ldquoheifer pasturerdquo
bull Always same pasture(s)bull Continuous use
bull Milking-depends on managementndash Drylot-little riskndash Grazing-evaluate situation
and diagnostics
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Common Situations-Zoo Hoofstock
bull Same issues with resistancebull Multi species exhibitsbull Evidence that integrated control strategies
can reverse resistance (Disney Animal Kingdom)
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Summary-What can we do nowbull Minimize other stressorsbull Maximize nutritionbull Understand parasites in your localebull Use best statistical analysis for FECRTsbull Think about refugiabull Think about pasture managementbull Donrsquot buy resistant wormsbull Proper product selection and usebull Cull poor-doers
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Bottom Linebull Balancing Act
ndash Short term economicsndash Long term sustainability
bull Donrsquot know how much we can give up now vs how much we will gain laterndash May never make up short
term losses
bull ldquoThe true meaning of life is to plant trees under whose shade you do not expect to sitrdquo Nelson Henderson
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Refugia
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
FECRT Summary
Control in General
Control in General
Pasture Rotation for Parasite Control
Clean vs Contaminated Pasture
Rotation of Dewormers
Use products properly
Keeping Refugia
Keeping Refugia
Keeping Refugia
Keeping Refugia
Replace Refugia
Pitfalls
Alternative Controls
Condensed Tannin Containing Plants
Copper-oxide Wire Particles
Worm-trapping Fungi
Vaccine
Alternative Control
New Products
Common Situations-Beef
Common situations-Beef
Common situations-Beef
Common Situations-Beef
Common Situations-Beef
Common Situations-Dairy
Common Situations-Zoo Hoofstock
Summary-What can we do now
Bottom Line
Refugia
Slide Number 102
Best Practices for Parasite Control in Beef and Dairy Cattle
Why me
Goals
Parasite Control Program vs Deworming Program
Parasite control recommendations are not made in a vacuum
Parasites
Slide Number 7
Life Cycle
Parasite Resistance in Livestock
Anthelmintic Resistance
Anthelmintic Resistance
Refugia
Slide Number 13
Anthelmintic Resistance
Genetics Worms
Gastrointestinal Nematode Resistance Across Active Ingredients
Selection Pressure
Slide Number 18
Are their lessons learned from other livestock species
Haemonchus contortus(Barber Pole Worm)
Why is H contortus such a problem
So What Happened in Sheep and Goats
Background to the Problem
Managing Toward Resistance
The End Result
Cattle Parasites
Cattle Ostertagia
Cooperia and Haemonchus placeii
Parasites in Cattle
Parasite Control Historical
Anthelmintic Resistance Situation in Cattle
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Anthelmintic Resistance in Cattle Parasites
Compounding Factors
Treatment failure ne Resistance
Slide Number 38
Non-Resistance ldquoTreatment Failuresrdquo
What Does All This Mean
What about diagnostics
Fecal Egg Count Reduction Test
FECRT Phenotypic Resistance
Cattle FECRT Issues
Cattle FECRT Issues
FECRT Issues
Hill Farm Research-Summer 2011(drought)
Dean Lee Research-Summer 2013(high rainfall and age)
Strongylid Eggs
Fecal Egg Counts
Other Diagnostics for Evaluating Resistance
Other Diagnostics for Evaluating Resistance
What About Control
Targeted Treatment (TT) and Targeted Selective Treatment (TST)
TST of SheepGoats
Selective Treatment
Five Point Checkcopy
Bottom Line-Goats in Louisiana
Beef Cattle
The Good
The Good
The Good
The Bad
The Ugly
The Ugly
The Ugly
Genetic Markers Animals
The Ugly
Now What
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
Best Management Practices Fecal Sample Collection and Quantitative Egg Counts for Detecting Anthelmintic Resistance in Cattle
