2. EWE EFFICIENCY
What is efficiency?
Why is it important?
What determines
efficiency?
How do you improve
efficiency?
3. WHAT IS EWE EFFICIENCY?
Number lambs born per ewe exposed
Number of lambs weaned per ewe exposed
Number of lambs produced (marketed or retained) per ewe exposed
4. WHAT IS EWE EFFICIENCY?
Pounds lamb weaned per ewe exposed
Pounds lamb produced (marketed or retained) per ewe exposed
Pounds of lamb produced per ewe body weight
Pounds of lamb produced per acre
5. WHAT IS EWE EFFICIENCY?
Profit per ewe
Profit per acre
6. WHY IS IT IMPORTANT?
Ewe efficiency is the driver of profitable sheep production
systems.
8. SIZE
WEIGHT & BODY CONDITION
Bigger ewes
Have more lambs
Have bigger lambs that reach target weights
sooner
But … they eat more
And . . . heavier weights may decrease efficiency.
Heavier, better conditioned ewes
Start cycling earlier in the breeding season
Have higher ovulation rates
Have higher conception rates
Give birth to heavier lambs
Produce more milk
Wean heavier lambs with higher survival rates
9. LONGEVITY
STAYABILITY, PRODUCTIVE LIFE SPAN
An underrated trait
Increased longevity . . .
Decreases culling rates
Reduces female replacement costs
More market lambs to sell
Puts more selection pressure on
replacement females.
Results in higher age-related
performance
Longer generation interval.
10. HOW TO INCREASE LONGEVITY
Longevity is a moderately heritable
trait
33% Iran study
27% UK study
No early life trait that facilitates
indirect selection
Correlation with body weight
Future - develop EBVs for longevity
11. HOW TO INCREASE LONGEVITY
Determine primary reasons for death and
culling in your flock
Don’t cull based on age
Maintain high performing ewes in flock for
longer
Select replacements from long-lived
parents
Crossbreed to increase longevity
12. LAMBING PERCENTAGE
NUMBER OF LAMBS PRODUCED ÷ NUMBER OF EWES EXPOSED (21 DAYS)
Primary factor determining profitability in sheep enterprise.
13. LAMBING PERCENTAGE
Composite trait
Fertility
Litter size (number lambs born)
Ovulation rate
Embryo survival
Lamb survival
Direct and maternal affects
Perinatal, pre- and post weaning
Affected by many different
factors
Genetics
Nutrition
Management
Season
Age
14. IMPROVING LAMBING PERCENTAGE:
FERTILITY (PREGNANCY RATE)
Maintain healthy flock
Proper ram management
Use fertile rams with high libido
breeding soundness exam (BSE)
Adequate ram power:
35 to 50 (mature ram) 15-25 (ram lamb)
Monitor breeding activity
Have ewes in good body condition at time of joining:
2.5 to 3.5
Flush ewes with body condition scores < 2
Provide good nutrition to ensure embryo survival
Select replacements from ewes that lamb in early
part of lambing season
Cull ewes that fail to breed in first heat cycle
15. IMPROVING LAMBING PERCENTAGE:
LITTER SIZE (NUMBER BORN) = OVULATION RATE + EMBRYO SURVIVAL
Maintain healthy flock
Have ewes in good body condition at time of
joining: 2.5 to 3.5
Flush ewes with body condition scores < 2
Proper nutrition to ensure embryo survival,
placental development, and birth of moderate-size
healthy lambs.
Breed in fall and lamb in spring
Maintain high-performing ewes in flock for longer
Reduce lambing interval: accelerated lambing
Select for litter size (H2=~10%)
Use ram with family history of multiple births
Select replacements from most productive ewes
EBVs for number born, number weaned
16. IMPROVING LAMBING PERCENTAGE: LAMB SURVIVAL
Timing
At birth
0-3 days
3-10 days
10 days until weaning
Post weaning
Causes
Abortion
Dystocia
Starvation
Hypothermia
Disease: scours, pneumonia, clostridial
Digestive problems
Internal parasites
Predators
When and why do lambs die?
17. IMPROVING LAMBING PERCENTAGE
LAMB SURVIVAL (0-10 DAYS)
Prevent losses due to abortion
biosecurity, vaccination, antibiotic therapy
Have ewes in good body condition at time of
lambing: 2.5 to 3.5
Proper late-gestation nutrition
Proper lambing environment: dry, draft free,
clean
Short lambing season
Attended lambing, jugging
Appropriate vaccination program
Select for lambing ease, mothering ability,
lamb vigor, milk production.
EBVs for number weaned.
19. LAMBS WEIGHTS AND FEED EFFICIENCY
Lamb weights
Pre-weaning
Pounds weaned
Post-weaning
Pounds marketed
Days to market
Market weights
Carcass weights
Market grade (?)
Feed efficiency
Lbs. feed per lb. of gain
Stocking rates
Cost of gain
20. IMPROVING LAMB WEIGHTS AND FEED EFFICIENCY
Lamb weights
Measure growth rates and calculate adjusted
weights and ratios.
Select for pre- and post-weaning growth in your
own flock.
Use rams documented to have superior growth
performance
On-farm performance testing
Central ram performance tests (PA, WV, VA)
Use EBVs for weaning, post-weaning, and yearling
weights.
Supplement forage diet for optimal performance.
Crossbreed to improve post-weaning growth.
Feed efficiency
Determine feed efficiency and cost of gain.
Use rams documented to have superior feed
efficiency
West Virginia Ram Performance Test
Hand-feed instead of self-feed
Whole grains instead of processed grains.
Improve pasture and grazing management
Supplement forage diet for better forage utilization
and optimal performance
Determine optimal ewe size for your production
environment.
21. OTHER FACTORS AFFECTING EFFICIENCY
Parasite resistance
need for deworming/monitoring
Hoof health
need for hoof trimming
Hair coat
need for shearing
Overall health and need for
treatment
Behavior
22. KEEP/CULL TO IMPROVE EFFICIENCY
Use parasite resistant rams
Cull ewes that require (frequent) deworming or are
heavy egg shedders.
Cull animals that require frequent hoof trimming
Cull animals with re-occurring hoof problems.
Cull animals that don’t respond to treatment for
hoof diseases.
Favor animals with dark-colored hooves (?)
Cull animals that require shearing
Cull ewes that require assistance at lambing.
Cull any animal that fails to thrive.
Cull animals with behavior problems.
23. BREED EWE LAMBS TO INCREASE EFFICIENCY
Ewes that are bred as lambs have a higher lifetime production that ewes bred for the first time as
yearlings.
Breeding ewe lambs speeds up genetic gain.
Evidence suggests that ewes that lamb at 1 year of age are better mothers at 2 years of age.
24. FACTS ABOUT EWE LAMBS
Ewe lambs have higher nutritional requirements than mature
ewes, because they are still growing.
Ewes lambs do not compete well with mature ewes.
Ewe lambs cycle later in the breeding season than mature ewes
– and stop cycling sooner.
Ewe lambs are less likely to seek out a ram
Ewe lambs are in estrus (standing heat) for a shorter period of
time
Ewe lambs have lower conception and pregnancy rates
Ewe lambs have lower ovulation rates
Ewe lambs produce less milk
25. TIPS FOR BREEDING EWE LAMBS SUCCESSFULLY
Feed replacement ewe lambs for moderate growth so
they reach their target breeding weights (60-70% of
mature weight).
Manage and feed ewe lambs separately from mature
ewes.
Mate ewe lambs separately and after mature ewes
Mate ewe lambs in confinement or small pastures
Mate ewe lambs to ram of same breed or breed with
smaller mature size
Jug ewes and lambs
Creep feed lambs
Wean lambs early
26. ESTABLISH BENCHMARKS FOR YOUR FARM
Trait Definition Goal
Fertility No. ewes lambing ÷ no. ewes exposed (21 days) 100%
Lambing percent No. lambs weaned ÷ no. ewes exposed > 200%
Percent triplet births Percent ewes giving birth to triplets > 33%
Birth weight Avg. birth weigh 8-10 lbs.
Lamb death loss Percent lamb deaths < 5 %
Pre-weaning ADG (Weaning weight - birth weight) ÷ age > 0.75
Pre-weaning ADG (Weaning weight - birth weight) ÷ age > 0.50
Lbs. lamb weaned Lbs. lamb weaned per ewe exposed > 150 lbs.
Efficiency Pounds of lamb weaned ÷ # ewes exposed >100%
Profit per ewe Income - expenses ÷ no. ewes >$150
Hoof growth Need for hoof trimming < 20%
Parasite resistance Need for deworming 0
27. THANK YOUR FOR YOUR ATTENTION.
ARE THERE ANY QUESTIONS OR COMMENTS?
SUSAN S CHOENIAN
Sheep & Goat Specialist
sschoen@umd.edu
www.sheepandgoat.