1. Carcass EPD: Where are we, and where are we going? Dan W. Moser Dept. of Animal Sciences and Industry Kansas State University

2. Carcass EPD Genetics of carcass composition Genetics of carcass composition Ultrasound-Carcass relationships Ultrasound-Carcass relationships How is ultrasound data incorporated into carcass EPD? How is ultrasound data incorporated into carcass EPD? How much progress are we making? How much progress are we making? Is standardization needed? Is standardization needed?

3. Genetics of Carcass Composition Good news! Good news!  Carcass traits are among the most highly heritable  When carcass data is available for use in selection, change can rapidly occur

4. Genetics of Carcass Composition Bad news! Bad news!  All animals with carcass data collected are dead!  Progeny testing for carcass traits is no trivial task  Cost  Identity  Time

5. Genetics of Carcass Composition Very little carcass data is being submitted to association databases Very little carcass data is being submitted to association databases Could instrument grading along with national animal ID result in greater amounts of carcass data reported? Could instrument grading along with national animal ID result in greater amounts of carcass data reported?

6. Ultrasound Ultrasound can estimate body composition in live animals Ultrasound can estimate body composition in live animals Ultrasound measurements in yearlings have fairly strong genetic correlations with carcass traits Ultrasound measurements in yearlings have fairly strong genetic correlations with carcass traits  Genetic correlation is the correlation in EPD for the pair of traits

7. How strong? Trait Genetic Correlation Fat About 0.70 Marbling/IMF 0.50 in one breed Ribeye area 0.70 to 0.90 Yearling wt/Carcass wt About 0.70

8. Why just 0.70? Age / developmental differences Age / developmental differences Steers vs. bulls Steers vs. bulls Position of measurement Position of measurement Measurement precision Measurement precision  Ultrasound IMF is good, not perfect  Carcass fat is good, not perfect Seventy percent of something is better than one-hundred percent of nothing Seventy percent of something is better than one-hundred percent of nothing

9. Unbiasedness Ultrasound data has less opportunity for bias Ultrasound data has less opportunity for bias  Data submitted by non-owners  Identity is much less of an issue  Maternal genetics are documented

10. Carcass EPD Carcass data only (no ultrasound) Carcass data only (no ultrasound)  Brahman  Gelbvieh  Shorthorn  All are collecting ultrasound data

11. Carcass EPD Ultrasound only Ultrasound only  Canadian Angus  Senepol  Many breeds in Australia

12. Carcass EPD Separate Carcass and Ultrasound EPD Separate Carcass and Ultrasound EPD  Angus

13. Combining Carcass and Ultrasound Carcass and Ultrasound measures can be jointly evaluated as correlated traits Carcass and Ultrasound measures can be jointly evaluated as correlated traits  Like weaning and yearling weights  Generates both carcass and ultrasound EPD  Both types of data affect both EPD

14. Which to print? Carcass Carcass  Economically relevant trait  Units consistent with grid marketing

15. Which to print? Ultrasound Ultrasound  Overwhelming majority of data  Gives a higher accuracy value in most cases  Breeder familiarity with values  Less subject to misidentification, bias

16. Accuracy Animals with ultrasound progeny, but no carcass progeny, can achieve only limited levels of accuracy for a true carcass EPD Animals with ultrasound progeny, but no carcass progeny, can achieve only limited levels of accuracy for a true carcass EPD

17. Carcass EPD Use both types of data, print carcass: Use both types of data, print carcass:  Braunvieh  Charolais  Chianina  Limousin  Maine-Anjou  Red Angus  Salers  Simmental

18. Carcass EPD Use both types of data, print ultrasound: Use both types of data, print ultrasound:  Brangus  Hereford

19. Retail Product Percentage Many equations have been developed to predict true retail product percentage from typical carcass measurements Many equations have been developed to predict true retail product percentage from typical carcass measurements Several breeds combine fat, ribeye, weight EPD into a retail product percentage or yield grade EPD Several breeds combine fat, ribeye, weight EPD into a retail product percentage or yield grade EPD  Using carcass, ultrasound, or both

20. Retail Product Percentage Percent retail product EPD Percent retail product EPD (higher values favorable):  Canadian Angus  Chianina  Maine-Anjou  Salers

21. Retail Product Percentage Yield Grade EPD Yield Grade EPD (lower values favorable):  Limousin  Simmental Yield Grade dollars EPD Yield Grade dollars EPD (higher values favorable)  Angus

22. Economic Indexes Any economic selection indexes or decision support tools will utilize information on carcass quality and cutability Any economic selection indexes or decision support tools will utilize information on carcass quality and cutability

23. Tenderness Three breeds have published Warner- Bratzler shear force EPD: Three breeds have published Warner- Bratzler shear force EPD:  Simmental  Updated, includes Calpain 316 genotypes  Hereford  Shorthorn

24. Angus Carcass Genetic Trend

25. Hereford Carcass Genetic Trend

26. Limousin Carcass Genetic Trend

27. Gelbvieh Carcass Genetic Trend

28. Progress? Most breeds are increasing ribeye area Most breeds are increasing ribeye area  Correlated with growth Only Angus and Red Angus seem to be increasing marbling very much Only Angus and Red Angus seem to be increasing marbling very much  Vast majority of IMF scans are Angus

29. Closing Thought Is standardization needed? Is standardization needed?  Printing carcass EPD on carcass vs. ultrasound scale  Various retail product equations