SELECTION TOOLS
Expected Progeny Difference (EPD) is the prediction of how future progeny of each animal are expected to perform rela- tive to progeny of other animals in the database. EPDs are expressed in units of the trait, plus or minus. Accuracy values are provided with the EPD and indicate the reliability of that EPD. An accuracy of close to 1.0 indicates higher reliability. This number is impacted by the number of progeny and ancestral records included in the analysis. EPDs should not be compared across breed prior to across-breed adjustments. Genomic-enhanced EPDs incorporate results from available genomic, or DNA, tests to increase reliability and accuracy of EPDs. Genomic tests available are specific to breed association. A. EPDs energy expenses). Components for computing the cow $EN savings difference include lactation energy requirements and energy costs associated with differences in mature cow size.
Calving Ease (CE/CED) - Expressed as a difference in percentage of unassisted births, with a higher value indicating greater calving ease in 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 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. Maternal Milk/Milk (MILK or MM) - Expressed in pounds, is a predictor of a sire’s genetic merit for milk and mothering ability as expressed in his daughters compared to daughters of other sires. It is the part of a calf’s weaning weight attributed to milk and mothering ability. Scrotal Circumference (SC) - Expressed in centimeters, is a predictor of the difference in transmitting ability for scrotal size compared to that of other sires. Stayability (STAY) - Expressed as a percentage, predicts the differences in the ability of an animals’ retained daughters to remain productive in the herd and calve every year through 6 years of age. Docility (DOC) - Percent of offspring achieving a docile (1) score. Marbling (MARB or MB) - 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 or 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. Yield Grade (YG) - Predicts difference in USDA Yield Grade score and expressed in USDA Yield Grade units. Calculated using genetic predictions of CW, REA, and FAT EPDs. B. Breed Specific EPD and/or Index: Angus: 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. Udder Suspension EPD (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. 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. Cow Energy Value ($EN) - expressed in dollar savings per cow per year, assesses differences in cow energy requirements as an expected dollar savings difference in daughters of sires. A larger value is more favorable when comparing two animals (more dollars saved on feed
Weaned Calf Value ($W) - an index, expressed in dollars per head, to predict profitability differences in progeny due to genetics from birth to weaning. The underlying objective being producers will retain 20% of the female progeny as replacements and sell the rest of the cull females and their male counterparts as feeder calves. Traits included are as follows (in no particular order): birth weight, weaning weight, milk, and mature cow weight. Maternal Weaning Calf Value ($M) - An index expressed in dollars per head that 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 male progeny as feeder calves. Traits included are: CED, CEM, WW, MILK, HP, DOC, MW, Claw, and Angle. Beef Value ($B) - Represents the expected average dollar-per-head difference in the progeny post-weaning performance and carcass value compared to progeny of other sires. The $B value is comprised of two pieces: feedlot ($F) and grid value ($G). Combined Value ($C) - An index, expressed in dollars per head, with the objective that 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. EPDs included are: CED, CEM, WW, YW, Milk, HP, DOC, MW, Angle, Claw, DMI, MARB, CW, REA and Fat. *Interim EPDs: Interim EPDs are calculated on animals during the time period between the weekly American Angus Association National Cattle Evaluations (NCE). An interim value is indicated by an “I” in front of the number. While admittedly low in accuracy, an interim value gives you a snapshot of the animal’s value as a parent, and, thus, it provides a temporary selection-decision tool until the next NCE run in which enough information is available to calculate a true NCE EPD Simmental & Black Hereford: Maternal Weaning Weight (MWW) - Pounds of weaning weight due to milk and growth. All-Purpose Index (API) - 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) - Evaluates sire for use on mature Angus cows with all offspring put on feed and sold grade and yield. Red Angus: Maintenance Energy (ME) - Expressed in Mcal per Month, is a predictor of the difference in maintenance energy requirement.
6 THE 4TH ANNUAL UNIV. OF WYOMING HIGH ALTITUDE BULL SALE
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