This is the 4th webinar in a five part series on Breeding Better Sheep & Goats. This presentation entitled "Performance Evaluation" was given by Susan Schoenian, University of Maryland Extension Sheep & Goat Specialist.

1. 2013 Winter Webinar Series: Breeding Better Sheep & Goats
Performance Evaluation
SUSAN SCHOENIAN
Sheep & Goat Specialist
University of Maryland Extension
sschoen@umd.edu - www.sheepandgoat.com

2. Making better sheep and goats
WHERE WE’VE BEEN WHERE WE NEED TO GO
Phenotype Genotype
Genotype + environment Genetic merit
Visual appraisal Performance evaluation
How animal looks How animal performs
Subjective criteria Objective criteria
What we see What we measure

3. Performance evaluation
Individual records Genetic predictors
• Adjusted weights • EPDs
• Milk yield • EBVs
• Fleece weight • DHIR
• Staple length
• Ultrasound data
• Fecal egg counts
• FAMACHA© scores
• Fiber analysis
• Performance ratios

4. Performance evaluation: set goals
• What is the primary
purpose of your sheep
and/or goat enterprise?
• If you are a seedstock
producer, what is the
primary role of your
breed(s) in commercial
production systems?
• Determine which traits are
most important to your
herd, flock, or breed.

5. Niche fiber
Color
Dairy Luster
Milk yield Handle
Percent protein Crimp
Percent fat Staple length
Udder conformation Fiber diameter
Linear appraisal Seedstock
Varies by breed
Scrapie genotype

6. Your selected traits
• Are they economically
important to your farm
and/or breed?
• Can the traits be
objectively measured
(when and how)?
• Will they respond to
selection or
(crossbreeding)?

7. Performance evaluation starts
with animal identification
Options
1. Ear notches
2. Tattoos
More permanent
3. Electronic
4. Ear tags
5. Paint brands
6. Neck chains

8. To make genetic improvement,
you have to keep good records.
• Everyone should keep basic
reproductive and health
records.
• What additional records you
keep (and data you collect)
will depend upon your
production emphasis and
breed.
• A central performance test
will collect data on potential
sires.

9. Record keeping options
Using a computer Handwritten
• Spreadsheet
1. Pocket book
• Database
2. Notebook
• Third party software
3. Chalkboard
• Online
• University

10. Keeping records by hand (pencil)

11. Spreadsheets for record keeping

12. Record keeping software
http://www.sheepandgoat.com/software.html#flock

13. Performance evaluation
• Records aren’t very useful
unless you use them for
decision- making purposes.
– Ram/buck selection
– Selection of replacements
– Keep/cull decisions
– Decisions to castrate
• Records need to be properly
analyzed and used to be
effective for genetic
improvement.

14. An important aspect of performance evaluation
Contemporary group
• Comparisons should only be
made between animals in
the same contemporary
group.
• A group of the same
breed, born within +/- two
weeks with each
other, raised at the same
location or in the same herd
or flock, of the same sex and
managed alike from birth
until time of measurement.

15. Factors affecting contemporary groups
• Breed percentage
• Sex
• Lambing/kidding period
• Location
• Management factors
– Health
– Nutrition Animals which receive preferential
treatment should be placed within
their own contemporary group.

16. Another important aspect of performance evaluation
Adjustments
• Sometimes records (data)
need to be “adjusted” to
remove environmental
effects.
• Records are adjusted to a
standard animal or weight
– Weaning weights
Single male offspring raised by a
3-6 year old dam.
– Loin eye area
125-lb. market lamb
100-lb. Katahdin ram lamb

17. Calculating adjusted weaning weights
1. Adjust weaning weights to a
common day of age (usually
60, 90, or 120 days of age)
a) Determine animal’s pre-
weaning average daily
gain (ADG).
b) Multiply pre-weaning ADG
by common age.
c) Add birth weight
2. Adjust weaning weight for sex
of offspring, age of dam, and
type of birth and rearing
a) Multiply age-corrected
weaning weight by
appropriate adjustment factor.

18. Adjustment factors allow animals to be fairly
compared by removing non-genetic factors.

19. Adjustment factors vary by species and breed. When breed-specific
adjustment factors are not available, generic adjustment factors can be used.

20. Adjustment factors for meat goats (Boer)

21. Example
• Calculate the 60-day adjusted weaning weight for a Dorset
ram lamb born on March 1 and weaned on June 10. The
lamb was born and raised as a twin. His birth weight was 10
lbs. He weighed 70 lbs at weaning. His dam was 2 years old.
1) Determine pre-weaning ADG
2) Multiply pre-weaning ADG weight by common age
3) Add birth weight back in
4) Multiply age-corrected weight by adjustment factor (see TABLE)

22. Born March 1
Born/raised twin
Weaned June 10
Birth weight - 10 #
Weaning weight - 70 #
Example Age of dam - 2 yrs
1) Determine pre-weaning ADG
(weaning weight - birth weight*) age (in days)
(70 - 10) 71 d = 0.85 lb/d
*If birth weight is not known, a weight per day of age (WDA) can be calculated instead.

23. Born March 1
Born/raised twin
Weaned June 10
Birth weight - 10 #
Example Weaning weight - 70 #
Age of dam - 2 yrs
2) Multiply pre-weaning ADG weight by common age
(0.85 x 60 d) = 51.0 lbs.
3) Add birth weight back in*
51.0 lbs. + 10 lbs. + 61.0 lbs.
*If WDA was calculated instead of pre-weaning ADG, do not add a birth weight back in.

24. Born March 1
Born/raised twin
Weaned June 10
Birth weight - 10 #
Example Weaning weight - 70 #
Age of dam - 2 yrs
4) Multiply age-corrected weight by adjustment factor
61.0 lbs. x adjustment factor
61.0 lbs. x 1.16 = 70.8 lbs.

25. Performance ratios
• The percent above or below the average of the
contemporary group.
• Performance ratio
Individual performance average performance of group x 100

26. Example: performance ratio
What is the WW ratio for buck #6
ID Adj. WW
1 44 Individual performance x 100
2 38
3 32
Average performance of group
4 50
5 48
6 45 45 lbs x 100
7 40 41.7 lbs
8 41
9 40
10 39 = 108 %
Avg 41.7

27. Selecting for parasite resistance
• Measure fecal egg counts Can only compare animals in
when animals are between 4 same contemporary group.
and 12 months of age.
• Compare average fecal egg
count of an individual lamb
or kid to the group average
(at least 15-25 animals).
• A high worm load is needed
to select for parasite
resistance (> 500 epg avg.)
• More measurements 
more selection accuracy
• A resistant male is needed to
make much progress.

28. Selecting for parasite resistance
SIRE SELECTION
• Choose sire with lowest
average progeny FEC.
REPLACEMENT SELECTION
• Choose replacements from
sire(s) with lowest average
FEC (if more than one sire)
• Choose replacements with
lowest FECs in group.

29. How we select for parasite resistance in our buck test
1
Top 10 2
3
4
5
6
7
8
9
10
10
9
8
7
Bottom 10 6
5
4
3
2
1
All goats were triple-dewormed (moxidectin + levamisole + albendazole) on 6/2.
Twelve days later, the average fecal egg count was near zero.

30. How we select for parasite resilience in our buck test
1
2
3
4 0
5
Top 10 6
7
8
9
10
10
9
8
7
6
Bottom 10 5
4
3
2
1
All goats were triple-dewormed (moxidectin + levamisole + albendazole) on 6/2.
For the next 8 weeks, the average FAMACHA© score improved and no goat required deworming.

31. What about visual appraisal?
Does it matter what the animal looks like?
Absolutely!

32. There should always be minimum standards for
reproductive soundness and structural correctness.
• Reproductive soundness
a) Testicles
b) Teeth
c) Teats and udder
• Structural correctness
a) Feet and legs
b) Jaw set
c) Conformation

33. Emphasis on visual appraisal
Commercial Show ring
• Minimum standards • Very important
• More stringent standards for • Economic trait
rams and bucks
• Some (?) correlation with • Some traits are highly
productivity and heritable.
longevity, especially with dairy • Low correlation with
females.
productivity.
• Many fleece traits are
subjectively evaluated.
Visual appearance is still a very important aspect of market acceptance.

34. Final webinar: Feb 19, 7 pm EST
“Advanced Genetic Improvement”