EPDs

What are EPDs and $Value Indexes?

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.

Value Index ($Value), an economic selection index allows multiple change in several different traits at once pertaining to a specific breeding objective. The $Value is an estimate of how future progeny of each sire are expected to perform, on average, compared to progeny of other sires if the sires were randomly mated to cows and if calves were exposed to the same environment.  

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. 

Maternal Epds

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), is 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 EPD (Milk), is a predictor of a sire's genetic merit for milk & mothering ability as expressed in his daughters compared to daughters of other sires. In other words, it is that part of a calf's weaning weight attributed to milk & mothering ability.

Mature Weight EPD (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 EPD (MH),expressed in inches, is a predictor of the difference in mature height of a sire's daughters compared to daughters of other sires.

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 energy expenses). Components for computing the cow $EN savings difference include lactation energy requirements and energy costs associated with differences in mature cow size.

Production Epds

Calving Ease Direct (CED), is 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 EPD (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 EPD (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 EPD (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), expressed in pounds per day, is a predictor of a sire’s genetic ability for postweaning 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 the difference in feed intake during the postweaning phase, compared to that of other sires.

Yearling Height EPD (YH), is a predictor of a sire's ability to transmit yearling height, expressed in inches, compared to that of other sires.

Scrotal Circumference EPD (SC), expressed in centimeters, is a predictor of the difference in transmitting ability for scrotal size compared to that of other sires.

Management Epds

Docility (Doc), is expressed as a difference in yearling cattle temperament, with a higher value indicating more docility. It predicts the average difference of progeny from a sire in comparison with another sire’s calves. In herds where temperament problems are not an issue, this expected difference would not be realized.

Claw Set EPD (Claw), is expressed in units of claw-set score, with a lower EPD being more favorable indicating a sire will produce progeny with more ideal claw set. The ideal claw set is toes that are symmetrical, even and appropriately spaced.

Foot Angle EPD (Angle), is expressed in units of foot-angle score, with a lower EPD being more favorable indicating a sire will produce progeny with more ideal foot angle. The ideal is a 45-degree angle at the pastern joint with appropriate toe length & heel depth.

Pulmonary arterial pressure EPD (PAP), 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.

Hair Shed EPD, is expressed in units of hair shed score, with a lower EPD being more favorable indicating a sire should produce progeny who shed their winter coat earlier in the spring. Selection for this trait should improve the genetic potential for a sire’s progeny to shed off earlier increasing the environmental adaptability of cattle living in heat stressed areas and producers grazing endophyte-infected (hot) fescue.

Carcass Epds

Carcass Weight EPD (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 EPD (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 EPD (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 EPD (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.

Group/progeny (C Grp/ Pg and U Grp/Pg) reflects the number of contemporary groups and the number of carcass and ultrasound progeny included in the analysis.

$Value Indexes

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.

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.

Feedlot Value ($F), an index, expressed in dollars per head, to predict profitability differences in progeny due to genetics for postweaning feedlot merit compared to the progeny of other sires. The underlying objective assumes producers will retain ownership of cattle through the feedlot phase & sell fed cattle on a carcass weight basis, but with no consideration of premiums or discounts for quality and yield grade. Traits contributing directly to the index are as follows: yearling weight (gain), carcass weight and dry-matter intake.

Grid Value ($G), an index, expressed in dollars per carcass, to predict profitability differences in progeny due to genetics for carcass grid merit compared to progeny of other sires. The underlying objective assumes producers will market cattle on an above-industry-average carcass grid. Traits included in the index are as follows (in no particular order): carcass weight, marbling, ribeye area, and fat.

Beef Value ($B), a terminal index, expressed in dollars per carcass, to predict profitability differences in progeny due to genetics for postweaning and carcass traits. This terminal index assumes commercial producers wean all male and female progeny, retain ownership of these animals through the feedlot phase and market these animals on a carcass grid. Traits included in the index are as follows: yearling weight, dry-matter intake, marbling, carcass weight, ribeye area and fat.

Combined Value ($C), an index, expressed in dollars per head, which includes all traits that make up both Maternal Weaned Calf Value ($M) and Beef Value ($B) 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).