Multiple Tools for IP Control

Dan Morrical

Iowa State University

515-294-0847

morrical@iastate.edu

Old way

Drugs, drugs, drugs

Newer, stronger, bigger doses

No longer sustainable

No new drugs

Tools available

Knowledge

Genetics

Selective treatment

Parasite resistance

Rotational grazing

Parasite resistance

Land resource

Knowledge

High risk animals

High risk times

Dry lot versus pasture

Stock density

Knowledge

Larvae levelsLarvae levels

Typical parasitic lifestyle

Eggs:

Development from egg to infective (L3) larvae can occur as early as 6 days

Molt into L1’s in the egg then hatch

Nematodirus develop into L3’s in the egg, then hatch

Most ova do not survive very cold ambient temperatures

Typical parasitic lifestyle

L3’s - infective stage

Thick cuticle protects them from dryingCannot feed - finite life span

Warm temperatures increase their metabolic rate.

Can survive some freezing

Haemonchus

Adults live in abomasumingest 0.05ml blood/worm/day

5000 worms will remove 250 ml of blood.

Adults are very prolific egg layers

Haemonchus L3’s are not as cold hardy as others

Most L3’s live for 1-3 months

Genetics

Katahdin and NSIP

Dorpers ?, Boer goats ?

Genetic resistance vs production

Selective treatment

FAMACHA

treat pale eyes

Labor

Faith

Resistance

Our parasites truly resistant

Fecal egg reduction test

Drenchrite

Refusia

Grazing management

Better forage productionBetter health statusEnough nutrients to feed sheep and parasites.

Land Resource

Pasture A Pasture B

Hayed in 07 grazed in 07

Grazed in 08 hayed in 08

Land Resource, option b

Pasture A Pasture B

Cattle in 07 Sheep in 07

Sheep in 08 Cattle in 08

Land Resource, option b

Pasture A Pasture B Pasture C

Cattle in 07Sheep in 07 Hayed 07

Hayed in 08 Cattle in 08 Sheep 08

Sheep in 09 Hayed in 09 Cattle 09

Safe pastures

No sheep or goats from either

July 1 to December 31

or

January 1 to June 30

Alternative approaches

Cat thyme Sericea Lespedeza Copper wire bolus Fungus DE

Research Design

Ewes:

0, .5, 1 and 2 g

Lambs:

0, .5, .75, 1.0 g

Results FEC

Ewes: Day 7FEC increased in ewes to >2000 epg

for 0 and .5 gram doseFEC decreased in ewes to <1000epg

for 2 g dose

Note: 2 g ewes went up to >1500epg on day 35

Results PCV

Ewes: from day 0 to day 21

all groups went down slightly

4 ewes had to be treated with PCV below 18

None were in the 2 gram group

Results AST

Lambs: no indication of copper problems

Ewes: no indication of copper problems

Base diet is pasture and TM salt

Applications

Extreme care2 gram dose is like feeding 25 PPM copper for 50 days

Documented resistance

Use serum AST with 2 g COWP in 5 ewes or less as first step

Summary

Drugs (anthelminics) are not the solution

Develop whole farm strategy Be creative Work with your Veterinarian

Questions