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Grazing Management Grazing Management to Meet Animal to Meet Animal Performance TargetsPerformance Targets
Mark KennedyMark Kennedy
State Grazinglands SpecialistState Grazinglands Specialist
USDA-NRCSUSDA-NRCS
Houston, MOHouston, MO
Meeting the Nutritional Needs Meeting the Nutritional Needs of Livestock from Pastureof Livestock from Pasture
INTAKEINTAKE
INTAKEINTAKE
INTAKEINTAKE
OverviewOverview
Balancing animal numbers and forage Balancing animal numbers and forage supplysupply
Matching diet quantity and quality needsMatching diet quantity and quality needs Matching grazing management and Matching grazing management and
paddock numberspaddock numbers
Animal Intake / Animal Intake / Stocking RateStocking Rate
There is only a certain amount of forage There is only a certain amount of forage produced in any plant community that is produced in any plant community that is available for use. Every acre can only available for use. Every acre can only support a finite amount of animal support a finite amount of animal weightweight
Matching the type and number of Matching the type and number of livestock to the forage base is very livestock to the forage base is very important for meeting animal targets as important for meeting animal targets as well as maintaining pasture conditionwell as maintaining pasture condition
The 1st Step: Balance Livestock Numbers with Forage Supply
• Stocking rate: The number of animals or animal liveweight assigned to a grazing unit on a seasonal basis.
• Carrying capacity: The stocking rate that provides a target level of performance while maintaining the integrity of the resource base.
• Stocking rate has a big effect on intake and availability.
Carrying capacity of pasture is determined by four factors
CarryingCapacity =
ForageProduction X Seasonal
Utilization Rate
DailyIntake X
Length of theGrazing Season
Carrying CapacityCarrying Capacity Example:Example:
Stocker operation(buying 500# selling 800#)Stocker operation(buying 500# selling 800#) 200 day seasonal grazing (April 1 - Oct. 20)200 day seasonal grazing (April 1 - Oct. 20) 16 paddock system (1-3 day grazing period)16 paddock system (1-3 day grazing period) 8000 lb. total forage production (from 8000 lb. total forage production (from
history/experience, soil survey, forage history/experience, soil survey, forage suitability groups)suitability groups)
Grazier’s ArithmeticGrazier’s Arithmetic
Then ….
Carrying Capacity =
8000 lb/acre X .65
.03 lb forage/lb liveweight X 200 days
= 867 lb liveweight / acre
Grazier’s ArithmeticGrazier’s Arithmetic
867 lbs. per acre/500 lb = 1.73 steers/ac867 lbs. per acre/500 lb = 1.73 steers/ac Can we stock 1.73 steers/ac initially?Can we stock 1.73 steers/ac initially?
If we expect them to grow to 800 lb. thenIf we expect them to grow to 800 lb. then 800 + 500 = 1300/2 = 650 (avg wt)800 + 500 = 1300/2 = 650 (avg wt)
867/650 = 1.33 steers/ac867/650 = 1.33 steers/ac
Forage Intake on Forage Intake on PasturePasture
Quantity/AvailabilityQuantity/Availability Proper stocking rates, grazing managementProper stocking rates, grazing management
QualityQuality Grazing management, species selectionGrazing management, species selection
Effect of Forage Availability Effect of Forage Availability on Relative Forage Intakeon Relative Forage Intake
How much does a 1,000 lbCow [email protected]% BW about 25lb DM
With limited availability 19 lb DM
Effect of Forage Availability Effect of Forage Availability on Relative Forage Intakeon Relative Forage Intake
IntakeIntake
75% Availability75% Availability Time spent grazingTime spent grazing
6–10 hours per day6–10 hours per day 6–10 hours ruminating6–10 hours ruminating
Biting rateBiting rate Cattle avg. 50 Cattle avg. 50
bites/minbites/min Bite sizeBite size
Cattle average 0.3 g Cattle average 0.3 g DM per biteDM per bite
Measured range of Measured range of 0.07 to 0.59 g per bite0.07 to 0.59 g per bite
Related to availabilityRelated to availability
25% forage quality25% forage quality
Factors Affecting IntakeFactors Affecting Intake
Dry matter intake =Dry matter intake =Biting Rate x Biting (grazing) Time x Bite Biting Rate x Biting (grazing) Time x Bite
SizeSize
Dry matter intake =Dry matter intake =
50 bites/min x 600 min/day x 50 bites/min x 600 min/day x 0.30.3 g/bite = g/bite =
9.0 kg or 9.0 kg or 19.8 lb DM 19.8 lb DM intake per dayintake per day
Factors Affecting IntakeFactors Affecting Intake
If bite size is only If bite size is only 0.070.07 g/bite g/bite
50 bites/min x 600 min/day x 50 bites/min x 600 min/day x 0.070.07 g/bite = g/bite =
2.1 kg or 2.1 kg or 4.6 lb DM4.6 lb DM intake per dayintake per day
If bite size is If bite size is 0.590.59 g/bite g/bite
50 bites/min x 600 min/day x 50 bites/min x 600 min/day x 0.590.59 g/bite = g/bite =
17.7 kg or 17.7 kg or 38.9 lb DM38.9 lb DM intake per day intake per day
6 - 10”
2 - 3”
Effect of Forage Availability Effect of Forage Availability on Relative Forage Intakeon Relative Forage Intake
The Quantity – Quality The Quantity – Quality CompromiseCompromise
Factors affecting forage quality
Plant maturity
Species
Plant Part
Factors affecting forage quality
Plant maturityGrowth stageLength of rest period
Plant Growth PhasesPlant Growth Phases
0.0
0.5
1.0
1.5
Spring Summer Fall
Yie
ld (
tons
/A)
Fescue Clover Annual Lespedeza
Orchardgrass Stockpile Birdsfoot Trefoil
Rest Period NeedsRest Period Needs
15
- 2
0 d
ays
20
- 2
5 d
ays
25
- 3
5 d
ays
35
- 4
5 d
ays
35
- 4
5 d
ays
30
- 3
5 d
ays
Factors affecting forage quality
Plant maturity
Species
Factors affecting forage quality
SpeciesLegumes > grassesAnnuals > perennialsCool-season > warm season
WinterWinter SpringSpring SummerSummer FallFall WinterWinter
J FJ F M A MM A M J J AJ J A S O NS O N DDLEGUME, Cool seanon grass – based
perennial pastures
Winter Annuals-rye, ryegrass, triticale,
brassicas
High Quality Hay/stockpiled
fescue
Winter Annuals – rye, ryegrass,
triticale,brassicas
High Quality Hay/stockpiled
fescue
Summer Annuals-
forage sorghums,
sudangrass, millet, corn, crabgrass,
perennial warm season grasses
Forage ChainForage Chain
Diversity is the KeyDiversity is the Key
Diverse pastures are Diverse pastures are more productivemore productive
Are less prone to Are less prone to disease and insect disease and insect damagedamage
Broadens nutritional Broadens nutritional opportunities of the opportunities of the grazing livestockgrazing livestock
Legumes provide Legumes provide nitrogen for the grass nitrogen for the grass and improve overall diet and improve overall diet qualityquality
Factors affecting forage quality
Plant part Leaves vs stems First bite vs second bite
1st bite: leaves with low fiberHigh quality
2nd bite: medium quality
3rd bite: stems with high fiber – lowquality – leave for regrowth
1. Maturity
2. Species
3. Plant Part
3 Factors Affecting Forage Quality
Animal Requirements vs Animal Requirements vs Forage Quality at Different MaturitiesForage Quality at Different Maturities
• Can use different stages of quality to our Can use different stages of quality to our advantageadvantage• Adjust body condition scoreAdjust body condition score
• Increase, maintain, or decrease body conditionIncrease, maintain, or decrease body condition
• Creep grazingCreep grazing• Calves allowed to creep gaze into higher quality Calves allowed to creep gaze into higher quality
pasturepasture
• ““Leader – Follower” grazingLeader – Follower” grazing• Animals with highest nutrient needs graze pasture Animals with highest nutrient needs graze pasture
first followed by those with lower nutritional needsfirst followed by those with lower nutritional needs
High Quality -First grazers
Medium quality - Last grazers
Expected Intake of Expected Intake of Different Quality ForagesDifferent Quality Forages
Intake as a Forage Quality
Relative Feed Value
% of Body Weight
---------------- ---------------- ---------------- Poor <80 1% Average 85-115 2% Good 120-140 2.5% Excellent >150 >3%
Estimated Nutrient Content of Estimated Nutrient Content of Tall Fescue at Different MaturitiesTall Fescue at Different Maturities
NDF NDF %%
ADF ADF %%
CP %CP %NEmNEm
Mcal/Mcal/lblb
NEgNEg
Mcal/Mcal/lblb
VegetativVegetativee
4949 2727 2020 0.700.70 0.390.39
Late bootLate boot 5757 3636 1616 0.580.58 0.290.29
MatureMature 7070 4242 88 0.530.53 0.230.23
Animal Requirements vs Animal Requirements vs Forage Quality at Different MaturitiesForage Quality at Different Maturities
IntakIntake % e % bwbw
Intake Intake lb DMlb DM
CPCP
lblbNEmNEm
McalMcalADGADG
lb/daylb/day
RequirementRequirement 2.52.5 15.015.0 1.61.6 5.25.2
PerformancePerformance
VegetativeVegetative 2.52.5 15.015.0 3.03.0 10.510.5 2.0+2.0+
Late bootLate boot 2.12.1 12.612.6 2.02.0 7.27.2 1.21.2
MatureMature 1.71.7 10.210.2 0.80.8 5.45.4 <0.5<0.5
600 lb beef steer, 2.0 lb ADG
Monitor your forage for Monitor your forage for qualityquality
Brix Meter
tests forage
pH Paper
monitor urineNUTBALanalyze manure
Grab Samplestests forage
Tried and true methodHow high is the pile?
Forage Quality:Forage Quality:Pancake batter, Pumpkin Pancake batter, Pumpkin Pies or Wedding Cakes?Pies or Wedding Cakes?
The Key to Successful The Key to Successful Grazing ManagementGrazing Management
FlexibilityFlexibility The ability to The ability to
adapt or modify, adapt or modify, being being responsive to responsive to changing changing conditionsconditions
Grazing Management Grazing Management ObjectivesObjectives
Have grazing animals take 1 large bite or Have grazing animals take 1 large bite or mouthful (animal intake) off of as many plants mouthful (animal intake) off of as many plants as possible in a pasture (Utilization)as possible in a pasture (Utilization)
Remove the animals from the pasture before Remove the animals from the pasture before any regrowth occurs and by the time 50% of any regrowth occurs and by the time 50% of the current growth has been removed (plant the current growth has been removed (plant persistence/health)(animal intake)persistence/health)(animal intake)
Have enough pastures to allow sufficient Have enough pastures to allow sufficient regrowth and rest before being grazed again regrowth and rest before being grazed again (rest/plant health) (animal intake)(rest/plant health) (animal intake)
Mark Kennedy, Ozarkian, 2007
Plant Growth and Management:Plant Growth and Management:
During grazing periods: control stubble height
•not too low—keep growing points•not too low—good photosynthesis for regrowth•not too low—keep roots growing•not too low – maintain bite size for intake
Between grazing periods: schedule rest periods
•allow photosynthesis •allow leaves to regrow to proper heights•not too long or forage quality declines
Plant Growth and Management:Plant Growth and Management:
• Example: 12 paddock system• Grazing period 2 day 3 day
4 day• Rest Period 22 day 33 day
44 dayFlexibility!
Matching Forage and Matching Forage and Animal ResourcesAnimal Resources
Enterprises with higher potential net Enterprises with higher potential net
return require higher quality pasture and return require higher quality pasture and
more intensive managementmore intensive management Greater forage yield per acreGreater forage yield per acre Forage quality should be betterForage quality should be better Management must be more intensiveManagement must be more intensive Number of paddocks should be greaterNumber of paddocks should be greater
Matching forage and livestock resources
Economic potential of grazing enterprisesEconomic potential of grazing enterprises
Pasture-based dairy/Beef finishingPasture-based dairy/Beef finishing
Dairy replacements /Beef stockersDairy replacements /Beef stockers
Sheep and goats, Cow-calf, HorsesSheep and goats, Cow-calf, HorsesPaddock #’s
So how many paddocks do I So how many paddocks do I need?need?
It dependsIt depends length of grazing period desiredlength of grazing period desired
producer goals, livestock performanceproducer goals, livestock performance length of rest period neededlength of rest period needed
Changes seasonallyChanges seasonally
rest period rest period grazing period grazing period + # herds = paddock + # herds = paddock
##
Grazing period NeedsGrazing period Needs
Plant based:Plant based: 2 - 5 days fast grow2 - 5 days fast grow 5 - 9 days5 - 9 days
moderatemoderate 9 - 12 slow 9 - 12 slow
growthgrowth
Animal Animal performance:performance: .5 - 1 day dairy .5 - 1 day dairy
cows/finishingcows/finishing 1 - 2 days 1 - 2 days
growing/fattening growing/fattening 2 - 5 days lactating 2 - 5 days lactating
beef cattle, sheep, beef cattle, sheep, horseshorses
Impact of Days on Paddock onImpact of Days on Paddock onChange in Sward CompositionChange in Sward Composition
0500
1000
1500
20002500
3000
3500
4000
DM
Av
aila
ble
(lb
/ac
re)
1 2 3 4 5 6 7 8 9 10 11 12 13
Days on Pasture
StemLeaf
0
5
10
15
20
25
30
OM
In
take
(lb
/hd
/day
)1 2 3 4 5 6 7 8 9 10 11 12 13
Days on Pasture
Impact of Days on Paddock Impact of Days on Paddock on Organic Matter Intakeon Organic Matter Intake
Rest period needsRest period needs Rest period needs:Rest period needs:
15 - 20 days during rapid growth15 - 20 days during rapid growth20 - 30 days during moderate growth20 - 30 days during moderate growth30 - 45 days during slow growth30 - 45 days during slow growth40 - 60 days very slow growth40 - 60 days very slow growth
How many paddocks do I How many paddocks do I need?need?
Paddock Number = Paddock Number = rest period rest period grazing period grazing period + 1+ 1
Ex:Ex: 20 day 20 day rest period - springrest period - spring 2 day 2 day grazing period grazing period +1 = 11+1 = 11 40 day 40 day rest period - summerrest period - summer 2 day 2 day grazing period grazing period + 1 = 21 + 1 = 21
How many paddocks do I How many paddocks do I need?need?
Or:Or:40 day rest period40 day rest period
4 day grazing period + 1 = 114 day grazing period + 1 = 11
Optimum Paddock #’s Optimum Paddock #’s based on Livestock Type based on Livestock Type (Rule of Thumb)(Rule of Thumb)
Livestock typeLivestock type Grazing PeriodGrazing Period
(Days)(Days)
Paddock #Paddock #
Dairy/grass Dairy/grass finishingfinishing
0.5 – 10.5 – 1 20 - 8020 - 80
Dairy heifer / beef Dairy heifer / beef stockersstockers
1 - 21 - 2 16 - 4016 - 40
Cow/calf, Sheep, Cow/calf, Sheep, Goats, HorsesGoats, Horses
2 - 52 - 5 8 - 168 - 16
SummarySummary Animals delight most to feed on fresh plantsAnimals delight most to feed on fresh plants Animals supplied with this kind of food would be Animals supplied with this kind of food would be
quickly fattedquickly fatted If a farmer divided his land into 15 - 20 equal divisions,If a farmer divided his land into 15 - 20 equal divisions, Stopped his beasts from roaming indiscriminatelyStopped his beasts from roaming indiscriminately Put the whole number of his beasts into one of these Put the whole number of his beasts into one of these
divisionsdivisions Have the number of beasts so great as to consume the Have the number of beasts so great as to consume the
best part of the grass in one daybest part of the grass in one day
Summary cont’d:Summary cont’d:
Give them a fresh park every morning to repeat the Give them a fresh park every morning to repeat the same repastsame repast
Have so many parks as days required to advance Have so many parks as days required to advance the grass to the proper length after being eaten the grass to the proper length after being eaten fare downfare down
So the first park would be ready to receive them So the first park would be ready to receive them after going over all the othersafter going over all the others
So they might be carried round in a constant So they might be carried round in a constant rotationrotation
James Anderson, Scottish Agriculturalist, 1777James Anderson, Scottish Agriculturalist, 1777
The EndThe End
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