Genetics of Horses and Livestock

5 Written Questions

1. Indicator of the expected change in one trait relative to change in another trait in a population.
2. Manage animals to keep environmental effects as similar as possible across the population.
3. -influences resemblance among relatives
   -influences accuracy of selection and rate of genetic change
4. Select for one trait at a time. After reaching the target for the first trait begin selecting for the next trait.
5. Multiple trait selection reduces selection intensity compared to selection for a single trait.

5 Matching Questions

1. Temporary Environmental Effect
2. Generation Interval
3. Selection Intensity
4. Truncation Selection
5. Repeated Traits

1. a Selection based on performance above a certain level.
2. b Time required to replace on generation with the next generation. Shorter interval = faster rate of genetic change.
3. c Strictness of selection criteria.
4. d Nutrition, track conditions, illnesses
5. e Traits for which individual animals have multiple performance records. (milk production, calf weaning weight)

5 Multiple Choice Questions

1. Calculate a combined "breeding value" based on several traits.
   1. Regression
   2. Generation Interval
   3. Selection Index
   4. Selection Intensity
2. Lists of genetic predictions, accuracy values, and other information for sires within a breed.
   1. Sire Summaries
   2. Trait Ratios
   3. Repeated Traits
   4. Regression
3. Genetic value as a parent. Indication of potential to contribute to offspring.
   1. Trait Ratios
   2. Producing Ability
   3. Repeated Traits
   4. Breeding Value
4. Reduce potential measurement error, use most precise measurement as possible.
   1. Accurate Measurement
   2. Regression
   3. Accuracy of Selection
   4. Replacement Rate
5. Grouping animals that experience similar environmental effects.
   1. Repeated Traits
   2. Trait Ratios
   3. Contemporary Grouping
   4. Correlation

5 True/False Questions

1. Gene Combination Value → Important for individual performance

   True        False

2. Repeatability → Measure of the strength of the relationship between repeated records for a trait in a population.

   True        False

3. Producing Ability → Measure of the strength of the relationship between P and BV for a trait in a population.

   True        False

4. Correlation → Indicator of the expected change in one trait relative to change in another trait in a population.

   True        False

5. Accuracy of Selection → Correlation between true BV and predicted breeding value for a trait in a population.

   True        False