Glossary of EPD’s
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.
$Value Indexes
, are multi-trait selection indexes, expressed in dollars per head, to assist beef producers
by adding simplicity to genetic selection decisions. The $Value is an estimate of how future progeny of
each sire are expected to perform, on average, compared to progeny of other sires in the database if the
sires were randomly mated to cows and if calves were exposed to the same environment.
PRODUCTION
Calving Ease Direct (CED)
, is expressed as a difference in percentage of unassisted births, with a higher
value indicating greater calving ease in first-calf heifers. It predicts the average difference in ease with
which a sire's calves will be born when he is bred to first-calf heifers.
Birth Weight EPD (BW)
, expressed in pounds, is a predictor of a sire's ability to transmit birth weight to
his progeny compared to that of other sires.
Weaning Weight EPD (WW)
, expressed in pounds, is a predictor of a sire's ability to transmit weaning
growth to his progeny compared to that of other sires.
Yearling Weight EPD (YW)
, expressed in pounds, is a predictor of a sire's ability to transmit yearling
growth to his progeny compared to that of other sires.
Residual Average Daily Gain (RADG)
, expressed in pounds per day, is a predictor of a sire’s genetic
ability for post weaning gain in future progeny compared to that of other sires, given a constant amount
of feed consumed.
Scrotal Circumference EPD (SC)
, expressed in centimeters, is a predictor of the difference in
transmitting ability for scrotal size compared to that of other sires.
MATERNAL
Maternal Milk EPD (Milk)
, is a predictor of a sire's genetic merit for milk and mothering ability as
expressed in his daughters compared to daughters of other sires. In other words, it is that part of a calf's
weaning weight attributed to milk and mothering ability.
Cow Energy Value ($EN)
, expressed in dollars 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.
Milk & Growth (M&G),
Maternal Milk & Growth reflects what the sire is expected to transmit to his
daughters for a combination of growth genetics through weaning and genetics for milking ability. It is an
estimate of daughters’ progeny weaning weight.
Maternal Weaning Weight (MWW),
Pounds of weaning weight due to milk and growth.
Maternal Calving Ease (MCE),
Percent of unassisted births in first-calving daughters.
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