American Angus Association Selection Tools
Expected Progeny Difference (EPD) , is the prediction of how future progeny of each animal are expected to perform relative to the progeny of other animals listed in the database. EPDs are expressed in units of measure for the trait, plus or minus. Interim EPDs may appear on young animals when their performance has yet to be incorporated into the American Angus Association National Cattle Evaluation (NCE) procedures. This EPD will be preceded by an “I”, and may or may not include the animal’s own performance record for a particular trait, depending on its availability, appropriate contemporary grouping, or data edits needed for NCE. Accuracy (ACC) , is the reliability that can be placed on the EPD. An accuracy of close to 1.0 indicates higher reliability. Accuracy is impacted by the number of progeny and ancestral records included in the analysis. PRODUCTION Calving Ease Direct (CED) , expressed as a difference in percentage of unassisted births, with a higher value indicating greater calving ease in first-calf heifers. It predicts the average difference in ease with which a sire’s calves will be born when he is bred to first-calf heifers. Birth Weight (BW) , expressed in pounds, is a predictor of a sire’s ability to transmit birth weight to his progeny compared to that of other sires. Weaning Weight (WW) , expressed in pounds, is a predictor of a sire’s ability to transmit weaning growth to his progeny compared to that of other sires. Yearling Weight (YW) , expressed in pounds, is a predictor of a sire’s ability to transmit yearling growth to his progeny compared to that of other sires. Residual Average Daily Gain (RADG) , feed efficiency expressed in pounds per day, is a predictor of a sire’s genetic ability for post-weaning gain in future progeny compared to that of other sires, given a constant amount of feed consumed. Dry Matter Intake (DMI) , expressed in pounds per day, is a predictor of difference in transmitting ability for feed intake during the post- weaning phase, compared to that of other sires. Yearling Height (YH) , expressed in inches, is a predictor of a sire’s ability to transmit yearling height compared to that of other sires. Scrotal Circumference (SC) , expressed in centimeters, is a predictor of the difference in transmitting scrotal size compared to that of other sires. MANAGEMENT Claw Set (Claw) , 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 compared to another sire. Foot Angle (Angle) , 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 compared to another sire. Docility (DOC) , expressed as a difference in yearling cattle temperament, with a higher value indicating more favorable docility in a sire’s offspring compared to another sire. Pulmonary Arterial Pressure (PAP) , expressed in millimeters of
Mercury (mmHg), with a lower EPD being more favorable indicating a sire should produce progeny with a lower PAP score to decrease the risk of progeny contracting high altitude disease most commonly experienced at 5,500 ft or greater in elevation. Hair Shed (HS) , expressed in units of hair shed score, with a lower EPD being more favorable. This indicates a sire should produce progeny who shed their winter coat earlier in the spring and has improved environmental adaptability in heat stressed areas and grazing endophyte-infected (hot) fescue. MATERNAL Heifer Pregnancy (HP) , is a selection tool to increase the probability or chance of a sire’s daughters becoming pregnant as first–calf heifers during a normal breeding season. A higher EPD is the more favorable direction, and the EPD is reported in percentage units. Calving Ease Maternal (CEM) , expressed as a difference in percentage of unassisted births, with a higher value indicating greater calving ease in first-calf daughters. It predicts the average ease with which a sire’s daughters will calve as first-calf heifers when compared to daughters of other sires. Maternal Milk (Milk) , expressed in pounds of calf weaned, is a predictor of a sire’s genetic merit for milk and mothering ability in his daughters. In other words, it is the part of the calf’s weaning weight attributes to milk and mothering ability. Teat Size (Teat) , expressed in units of teat size score, with a higher EPD indicating a sire will produce daughters with smaller teat size compared to that of other sires’ daughters. Udder Suspension (UDDR) , expressed in units of udder suspension score, with a higher EPD indicating a sire will produce daughters with tighter udder suspension compared to that of other sires’ daughters. Functional Longevity (FL) , expressed in number of calves, is a predictor of the number of calves a sire’s daughters are predicted to produce by 6 years of age compared to that of other sires’ daughters. A higher EPD is the more favorable direction indicating more calves produced on average. Mature Weight (MW) , expressed in pounds, is a predictor of the difference in mature weight of daughters of a sire compared to the daughters of other sires. Mature Height (MH) , expressed in inches, is a predictor of the difference in mature height of a sire’s daughters compared to daughters of other sires. CARCASS 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. 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 (RE) , expressed in square inches, is a predictor of the difference in ribeye area of a sire’s progeny compared to progeny of other sires. Fat Thickness (Fat) , expressed in inches, is a predictor of the differences in external fat thickness at the 12th rib (as measured between the 12th and 13th ribs) of a sire’s progeny compared to progeny of other sires.
Page 43
Made with FlippingBook - Share PDF online