AMERICAN ANGUS ASSOCIATION SELECTION TOOLS Expected Progeny Difference (EPD), is a prediction of how future progeny of each animal are expected to perform relative to the progeny of other animals in the database. EPDs are expressed in units of measure for the trait.
Expected Progeny Difference (EPD), is a prediction of how future progeny of each animal are expected to perform relative to the progeny of other animals in the database. EPDs are expressed in units of measure for the trait. The factors affecting EPDs are an animal’s ancestors, individual performance within its contemporary group and its genomics. While EPDs assist in removing some of the guesswork, they are merely a guide and are only a predictive tool. PRODUCTION CED (Calving Ease Direct) is expressed as a difference in percentage of unassisted births in first-calf heifers, with a higher value indicating greater calving-ease. Breed average is +7. BW (Birth Weight) , expressed in pounds, is a predictor of a sire’s ability to transmit birth weight to his progeny compared to that of other sires. Breed average is +1.2. WW (Weaning Weight) , expressed in pounds, is a predictor of a sire’s ability to transmit pre-weaning growth to his progeny compared to that of other sires. Breed average is +66. YW (Yearling Weight) , expressed in pounds, is a predictor of a sire’s ability to transmit post- weaning growth to his progeny compared to that of other sires. Breed average is +118. SC (Scotal Circumference) , expressed in centimeters, is a predictor of the difference in a sire’s ability to transmit scrotal size compared to that of other sires. Breed average is +.87. MATERNAL HP (Heifer Pregnancy) , is a selection tool to increase the probability of a sire’s daughters becoming pregnant as heifers during a normal breeding season. Breed average is +11.1. MM (Maternal Milk) is a predictor of a sire’s genetic merit for milk as expressed in his daughters compared to daughters of other sires. In other words, it is the part of a calf’s weaning weight attributed to milk. Breed average is +26 MANAGEMENT DOC (Docility) is expressed as a difference in yearling cattle temperament, with a higher value indicating more favorable docility. Breed average is +19.
CLAW SET, is expressed in units of claw-set score. A lower EPD is more favorable, indicating a sire will produce progeny with more symmetrical, even and appropriately spaced toes. Breed average is +.49. FOOT ANGLE , is expressed in units of foot-angle score. A lower EPD is more favorable, indicating a sire will produce progeny with an angle closer to 45 degrees at the pastern and appropriate toe length and heel depth. Breed average is +.48. PAP (Pulmonary arterial pressure) , is expressed in millimeters of Mercury (mmHg), with a lower EPD being more favorable indicating a sire should produce progeny with a lower PAP score. PAP score is an indicator of susceptibility to high altitude disease commonly experienced at elevations greater than 5,500 feet. Selection for this trait aims to improve the genetic potential for a sire’s progeny to have lower PAP scores thus a lower chance of contracting high altitude disease increasing the environmental adaptability of cattle living in mountain areas. Breed average is +1.15. CARCASS MB (Marbling EPD) , expressed as a fraction of the difference in USDA marbling score of a sire’s progeny compared to progeny of other sires. Breed average is +.61. RE (Ribeye Area EPD), expressed in square inches, is a predictor of the difference in ribeye area of a sire’s progeny compared to progeny of other sires. Breed average is +.63. $VALUE SELECTION INDEXES Selection indexes are a tool to select for several traits simultaneously, while taking into account genetic and economic values. $Values encompass the revenue generated from genetically derived outputs and associated costs from required inputs.
$M (Maternal Weaned Calf Value) , expressed in dollars per head, predicts profitability differences in progeny from conception to weaning by decreasing mature cow size and improving docility, foot structure and fertility while maintaining weaning weights consistent with current production. Breed average is +61. $C (Combined Value) , expressed in dollars per head, includes $M and $B with the objective that a producer will replace 20% of their breeding females per year with heifers retained, while the producer retains ownership of all remaining male and female progeny though the feedlot and sold on a carcass merit grid. Breed average is +253. Dam’s Production lists the number of calves measured from the dam and their average ratio for the given trait. PERFORMANCE DATA BW: Actual Birth Weight WW: Weaning Weight adjusted to an age- constant of 205 days. YW: Yearling Weight adjusted to an age-constant of 365 days. SC: Scrotal Circumference adjusted to an age- constant of 365 days. IMF: Percent Intramuscular Fat (indicator trait for Marbling) adjusted to an age constant of 365 days. RE: Ribeye Area, measured in sq. cm, adjusted to an age constant of 365 days. Ratio: Ranking within a contemporary group. A ratio of 100 is average for the group, while 105 is 5% above average for the group.
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Nov. 8, 2025
bred for balance
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