Enterprise: Animal Science
Unit:Livestock selection
Factor
Information needed
I. Intro. A. High quality livestock programs
must have the ability to select
quality animals.
II.
A. Some traits that are profitable and
General common in all species.
Selection B. General female traits
1. Healthy
2. Femininity and type
3. Size for age
4. Reproductive efficiency
5. Longevity
C. Rules of thumb for culling females
1. Failure to reproduce
2. Wean light-weight or low grade
offspring.
3. Develop a bad mammary system
4. Develop an incurable defect
5. Hereditary disease
6. Poor conformation
D. Male selection traits
1. contribute 50% of genetics to
offspring, making them more
important than any one female.
2. Select to improve herd weaknesses
3. Use pedigree information
4. Use performance data when
possible
5. Good conformation is a must
6. Select for use of offspring (market
or breeding?)
E. Market (feeder) animal selection:
1. Efficiency of gain
2. Healthy
3. Growth rate
4. Non-castrated males cause
problems
5. Females generally reach grade
and maturity faster, but yield lower
(beef especially)
6. Buy weaned and pre-conditioned
animals
III.
A. Each species has its own traits to
Species select for.
selection B. Livestock judging gives students
the chance to apply learned ideals.
C. Learn to recognize the ideal and
make judgments based upon that
ideal.
1. Beef are selected for muscle,
body volume, and structural
correctness.
a. Market animals must be fat
enough to grade choice
Ideal Breeding Heifer
Judging 101
Ideal Market Steer
Judging 101
2. Sheep are selected for muscle,
trimness, size and scale, and structural
correctness.
Ideal
Breeding
Ewe
Judging 101
Ideal Market Lamb
a. Lambs must be lean Judging 101
3. Swine are selected on the five L’s
a. Long, level, loose, lean, and
large (muscling and size)
Ideal
Breeding
Gilt Judging 101
Ideal Market Hog- Side View
Ideal Market Hog- Rear View
a. Market hogs must be lean
Judging 101