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What is an EPD?. Expected Progeny Difference “the differences in performance expected from the offspring of one individual compared to the offspring of another individual, within the same breed”. Ensminger and Perry, 1997. Birth Weight EPD. Indicates calving ease Measured in pounds of calf
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What is an EPD? • Expected Progeny Difference • “the differences in performance expected from the offspring of one individual compared to the offspring of another individual, within the same breed” Ensminger and Perry, 1997
Birth Weight EPD • Indicates calving ease • Measured in pounds of calf • Expected birth weight difference of calves, excluding maternal influence Johnson, 1997
Weaning Weight EPD • Indicates growth performance at weaning (205 day weight) • Measured in pounds of calf Johnson, 1997
Yearling Weight EPD • Indicates post-weaning performance (365 day weight) • Measured in pounds of calf Johnson, 1997
Milk EPD • Measured in pounds of weaning weight produced by daughters • Excludes genetics for growth Johnson, 1997
Total Maternal EPD • Calculated as follows: 1/2 weaning weight EPD + all of the milk Total Maternal EPD Johnson, 1997
Scrotal Circumference EPD • Measured in centimeters • Indicates fertility and age at puberty of offspring Johnson, 1997
Carcass EPDs • Carcass Weight (Pounds of carcass) • Marbling (USDA marbling degrees) • Ribeye Area (Square inches) • Fat thickness (Inches) Johnson, 1997
Accuracy • Measures reliability of EPDs. • Young animals without a lot of offspring have lower accuracy • Animals with lots of offspring will have higher accuracy Johnson, 1997
EPD Cautions • Not comparable between breeds, only within a breed • Average breed EPDs do not equal zero, look them up in latest sire summary for the breed Johnson, 1997
EPD Cautions • EPDs do NOT predict absolute performance • The biggest is not always the best - use to fit animals to the environment (scenario) • Examples - milk and growth Johnson, 1997