Carcass EPDs:
Carcass Weight (CW): Expressed in pounds is a predictor of the differences in hot carcass weight of a sire's progeny compared to progeny of other sires.
Yield Grade (YG): A measure of the relative proportion of closely trimmed, boneless retail cuts from the bull's progeny. Higher EPDs mean higher yield grades, and thus a lower proportion of retail cuts.
Marbling (MARB): Expressed as a fraction of the difference in USDA marbling score of a sire's progeny compared to progeny of other sires.
Ribeye Area (REA): Expressed in square inches, is a predictor of the difference in ribeye area of a sire's progeny compared to progeny of other sires.
$ Values/Indexes:
All-Purpose Index (API): Expressed in dollars per cow exposed under an all-purpose-sire scenario. Evaluates sires for use on the entire cow herd (bred to both Angus first-calf heifers and mature cows) with the portion of their daughters required to maintain herd size retained and the remaining heifers and steers put on feed and sold grade and yield. Terminal Index (TI): Expressed in dollars per cow exposed under a terminal-sire scenario. Evaluates sire for use on mature Angus cows with all offspring put on feed and sold grade and yield. Maternal Weaned Calf Value ($M): An index, expressed in dollars per head, predicts profitability differences from conception to weaning with the underlying breeding objective assuming that individuals retain their own replacement females within herd and sell the rest of the cull female and all male progeny as feeder calves. The model assumes commercial producers will replace 25% of their breeding females in the first generation and 20% of their breeding females in each subsequent generation. Traits included are as follows: calving ease direct, calving ease maternal, weaning weight, milk, heifer pregnancy, docility, mature cow weight, claw set and foot angle. Beef Value ($B)— a terminal index, expressed in dollars per carcass, to predict profitability differences in progeny due to genetics for post weaning and carcass traits Combined Value ($C): An index, expressed in dollars per head, which includes all traits that make up both Maternal Weaned Calf Value (SM) and Beef Value (SB) with the objective that commercial producers will replace 20% of their breeding females per year with replacement heifers retained within their own herd. The remaining cull heifer and steer progeny are then assumed to be sent to the feedlot where the producers retain ownership of those cattle and sell them on a quality-based carcass merit grid. Expected progeny differences (EPDs) directly influencing a combined index: calving ease direct (CED) and maternal (CEM), weaning weight (WW), yearling weight (YW), maternal milk (Milk), heifer pregnancy (HP), docility (DOC), mature cow weight (MW), foot angle (Angle), claw set (Claw), dry matter intake (DMI), marbling (Marb), carcass weight (CW), ribeye area (RE) and fat thickness (Fat).
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