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AMERICAN ANGUS ASSOCIATION EPD DEFINITIONS
PRODUCTION
•
CALVING EASE DIRECT (CED)
, is expressed as a difference in
percentage of unassisted births, with a higher value indicating great-
er 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 EPD)
, 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 EPD)
, 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 EPD)
, 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 postwean-
ing gain in future progeny compared to that of other sires, given a
constant amount of feed consumed.
•
YEARLING HEIGHT EPD (YH)
, is a predictor of a sire’s ability
to transmit yearling height, expressed in inches, compared to the 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.
•
DOCILITY (DOC)
, is expressed as a difference in yearling cattle
temperament, with a higher value indicating more favorable docility.
It predicts the average difference of progeny from a sire in compar-
ison with another sire’s calves. In herds where temperament prob-
lems are not an issue, this expected difference would not be realized.
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.
CARCASS
•
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 pre-
dictor 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 mea-
sured between the 12th and 13th ribs) of a sire’s progeny compared
to progeny of other sires.
$VALUE INDEXES
$Value indexes are multi-trait selection indexes, expressed in dollars per
head, to assist beef producers by adding simplicity to genetic selection
decisions. The $Value is an estimate of how future progeny of each sire
are expected to perform, on average, compared to progeny of other sires
in the database if the sires were randomly mated to cows and if calves
were exposed to the same environment.
•
WEANED CALF VALUE ($W)
, an index value expressed in
dollars per head, is the expected average difference in future progeny
performance for preweaning merit. $W includes both revenue and
cost adjustments associated with differences in birth weight, weaning
direct growth, maternal milk, and mature cow size.
•
FEEDLOT VALUE ($F)
, an index value expressed in dollars per
head, is the expected average difference in future progeny perfor-
mance for postweaning merit compared to progeny of other sires.
•
GRID VALUE ($G)
, an index value expressed in dollars per head,
is the expected average difference in future progeny performance for
carcass grid merit compared to progeny of other sires.
•
BEEF VALUE ($B)
, an index value expressed in dollars per head,
is the expected average difference in future progeny performance for
postweaning and carcass value compared to progeny of other sires.
For more information on how to use this information in your breeding program, visit the American Angus Association website:
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, appropri-
ate contemporary grouping, or data edits needed for NCE.
EPDs are enhanced by genomic profiles generated by Zoetis and GeneSeek, when applicable.
$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.
