1 / 24

USDA Genetic Evaluations for Type Traits

USDA Genetic Evaluations for Type Traits. Type Traits. Describe physical characteristics of animal Final Score (overall assessment) Scored  50-99 Linear traits (13 traits) Scored 1-50. History of Type Evaluations. 1986 – Sire model for final score 1988 – Collection of linear traits

cicely
Download Presentation

USDA Genetic Evaluations for Type Traits

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. USDA Genetic Evaluations for Type Traits

  2. Type Traits • Describe physical characteristics of animal • Final Score (overall assessment) • Scored  50-99 • Linear traits (13 traits) • Scored 1-50

  3. History of Type Evaluations • 1986 – Sire model for final score • 1988 – Collection of linear traits • 1989 – Sire model for linear traits • 1995 – Multi-trait animal model • 2000 – Base change • 2005 – Base change

  4. Numbers of Appraisals of Does

  5. Appraisals for Does in 2005(n=4,593)

  6. Evaluation model • An equation that indicates what factors contribute to an observation • Separates the genetic component from other factors • Solutions used to predict the genetic potential of progeny

  7. Type Evaluation Model MODEL: y = h + a + p + e y = Adjusted type record h = Herd appraisal date a = Animal genetic effect (breeding value) p = Permanent environment Non-genetic effect common to all a doe's appraisals e = Unexplained residual

  8. Multi-trait Model • Scores from one trait affect the evaluation of other traits through the genetic correlations

  9. Genetic Correlations

  10. Genetic Parameters • Heritability – Portion of variation due to genetics • Repeatability – Similarity of repeated records, includes genetic and permanent environmental effects

  11. Heritability and Repeatability

  12. Genetic Change per year from does born 1990 – 2003

  13. Breeding value trend for type

  14. Herds for Bucks Born 1999 – 2003(n=2,451)

  15. Daughters for Bucks Born 1999 – 2003(n=2,451)

  16. Distribution of Reliability for Final Score

  17. Methods of Expressing evaluations • Estimated breeding value (EBV) • Animal’s own genetic value • Predicted transmitting ability (PTA) • ½ EBV • Expected contribution to progeny

  18. Combining type and production Production-Type index (PTI) • Combines yield and type evaluations into a single value • There are 2 versions: • PTI 2:1, weights 2 production : 1 type • PTI 1:2, weights 2 type : 1 production

  19. AIPL web services http://aipl.arsusda.gov/query/public/tdb.shtml#GoatsTBL • Queries provide display of: • Pedigree information • Yield records • Herd test characteristics • Genetic evaluations of does & bucks • Yield • Type • Access information using: • ID number • Animal name • Herd code

  20. 1918

  21. 1947

  22. 1977

  23. 2003

  24. Summary • Type data contributes to genetic evaluations of Final Score and 13 linear traits • Multi-trait Animal Model combines information from all relatives and traits • Few bucks have many daughters in many herds so reliability is low • Production-type index combines evaluations • Substantial genetic progress is occurring in several traits

More Related