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DGM:ISU:2013
Sheep and Pastures
Dr. Dan “Grumpy” MorricalSheep Extension SpecialistAnimal Science Department
DGM:ISU:2013
Uniqueness of Sheep
Small mouth sizeallows selective grazing
Mobile lipsallows selective grazing
Higher intake a % of bodyweightcompared to cows
Can be controlled by electric fence
DGM:ISU:2013
Uniqueness of Sheep
Diet preference Grass Forbs
ShrubsSheep 50 30 20
Cattle 70 15 15
Goats 30 10 60
Van Dyne et al. 1980
DGM:ISU:2013
Sheep and Pastures
Dr. Dan “Grumpy” MorricalSheep Extension SpecialistAnimal Science Department
Challenges
• Assessing status• Intake• Diet Selectivity• Nutrient content of
forage
Status
• Body condition• Fill • Contentedness
Factors that impact intake
• Forage available• Bite size and bite rate• Feed quality & rate of
passage48-96 hrs
• Grazing time and weather
YOURLOGOHERE
Can my pasture provide forageneeded to meet grazing needs?
ISU Beef Teaching– 54 acres of pasture– primarily bluegrass and bromegrass, some
white clover ( ~ 30%)
10 inch brome
Increasing intake• Rotational grazing• Stocking rate vs output
per acre• Manage feed quality• Intake levels
2.5-4.5% of bodyweight
YOURLOGOHERE
Can my pasture provide forageneeded to meet grazing needs?
ISU Beef Teaching– 54 acres of pasture– primarily bluegrass and bromegrass, some
white clover ( ~ 30%)
10 inch brome
Animal selectivity• Just because
it is there does not mean animals will eat it.
• Diet quality is higher than average
• Must have adequate dry matter available
Pasture sampling• Grab samples
easyaccurate ??
• Clip arealaboraccurate
• Number of samples
• Using and interpreting reports
Stockpiled grazing • Forage quality• Forage quanity• When to
stockpile• Nitrogen
fertilization• Grazing and
growing seasons are not the same
Grazing weaned lambs• Quality of forage is more
important• Lambs have limited intake• Higher protein requirements
gains generally highest on legumesWhy?
• Parasites control is more critical• Supplementation
What nutrient is likely short?
ISU Work with Supplemention
• Lambs on cool season grass pastures continuously grazed
• Supplemented at 2% of bodyweight• Control was straight corn
conversion of extra corn was 10-1• Experimental diets were fortified with various
protein sources ( SBM, Fish, Blood, CGM)gain response to escape protein .35 vs. 25
NOT ECONOMICAL
Forage Budgeting in Grazing Systems by Integrating Plant and
Animal Management
Goals of Grazing ProgramConvert sunshine into lean tissue
Individual vs group
Sustain or improve pasture
Rumination Time
• Amount of time relates to grazing time
• Much occurs at night• Diurnal patterns and Seasonal
patterns• Fiber level
Forage plants
• Think of them as biochemical factory
• Goal is to capture and convert solar energy into plant energy
YOURLOGOHERE
Can my pasture provide forageneeded to meet grazing needs?
ISU Beef Teaching– 54 acres of pasture– primarily bluegrass and bromegrass, some
white clover ( ~ 30%)
10 inch brome
Factors that impact output• Fertility/soil• Water• Sunshine• Temperature• Species
Factors that impact output• Fertility/soil• Water• Sunshine• Temperature• Species
Factors that impact output
• Fertility N
40-200 pounds per acre
P and Ksoil test
• Legume vs grass
YOURLOGOHERE
Can my pasture provide forageneeded to meet grazing needs?
ISU Beef Teaching– 54 acres of pasture– primarily bluegrass and bromegrass, some
white clover ( ~ 30%)
10 inch brome
Factors that impact output
• Fertility N
40-200 pounds per acre
P and Ksoil test
• Legume vs grass
YOURLOGOHERE
Can my pasture provide forageneeded to meet grazing needs?
ISU Beef Teaching– 54 acres of pasture– primarily bluegrass and bromegrass, some
white clover ( ~ 30%)
10 inch brome
Factors that impact output
• WaterDroughtRoot depthMost droughty forage?
Factors that impact output
• Sunshineweatherdensity of forageleaf area
• Temperaturecool seasonwarm season
Factors that impact output• Species
productivitypoorest bluegrassintermediate bromehighest reed canary
warm season vs cool season
Most common problem
• too little growth • too many animals
• pasture and animals not in balance
Forage growth
• How fast?• First cutting hay
2 tons per acreassuming 60 day accumulation 67 pounds per day 3 horses or 2 cows
Forage growth• Concerns with my logic ?
uniform growth100% utilizationcomplete rest
Animal selectivity• Just because it is there does not mean
animals will eat it.• Species differences
goatssheephorsescattle
More paddocks means more rest, more productivity.
0102030405060708090
100
1 2 3 4 5 6 8 10 12 16 20
Number of Paddocks
% R
est
Can my pasture provide forage needed to meet
grazing needs?• ISU Beef Teaching
54 acres of pastureprimarily bluegrass and bromegrass,
some white clover ( ~ 30%)• 10 inch brome
Ewe Grazing Days Per Acre
BFT: KyBG 1429 1973BFT: SBG 1474 2122BFT: OG 1446 2028Cost $40.00/year 2 of 3 years were drought
DGM:ISU
Peter Woods, WI
a
a
3 Year High
Average Year
DGM:ISU
