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

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?

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

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

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?

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

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

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

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

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

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

Carcass EPD Separate Carcass and Ultrasound EPD Separate Carcass and Ultrasound EPD  Angus

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

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

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

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

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

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

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

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

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

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

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

Angus Carcass Genetic Trend

Hereford Carcass Genetic Trend

Limousin Carcass Genetic Trend

Gelbvieh Carcass Genetic Trend

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

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