4
Expected Progeny Difference (EPD),
is the prediction of how future
progeny of each animal are expected to perform relative to the proge-
ny 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.
GROWTH
Calving Ease Direct (CED)
, is expressed as a difference in percent-
age of unassisted births, with a higher value indicating greater calving
ease in first-calf heifers. It predicts the average difference in ease with
which an 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.
Yearling Height EPD (YH)
, is a predictor of a sire’s ability to trans-
mit yearling height, expressed in inches, compared to the that of other
sires.
Scrotal Circumference EPD (SC)
, expressed in centimeters, is a pre-
dictor of the difference in transmitting ability for scrotal size compared
to that of other sires.
CARCASS
The new carcass EPDs are calculated from an integrated analysis of the
Angus Herd Improvement Records (AHIR
®
) carcass and ultrasound
phenotypic databases. The genetic evaluation produces a single set of
EPDs for carcass weight, marbling score, Ribeye area and fat thick-
ness. The units of measure are in carcass trait format and analyzed on
an age-constant basis.
Carcass Weight EPD (CW)
, expressed in pounds is a predictor of the
differences in hot carcass weight of a sire’s progeny compared to prog-
eny 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 prog-
eny of other sires.
MATERNAL
Calving Ease Maternal (CEM),
is expressed as a difference in per-
centage of unassisted births with a higher value indicating greater calv-
ing 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 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 wean-
ing weight attributed to milk and 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 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.
$VALUE INDEXES
$Value indexes
, are multi-trait selection indexes to assist beef produc-
ers by adding simplicity to genetic selection decisions. $Values are
reported in dollars per head, where a higher value is more
favorable.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 performance for
postweaning merit compared to progeny of other sires.
Grid Value ($G)
, an index value expressed in dollars per head, is the
expected average difference in future progeny performance for carcass
grid merit compared to progeny of other sires.
Quality Grade ($QG)
represents the quality grade segment of the eco-
nomic advantage found in $G. $QG is intended for the specialized user
wanting to place more emphasis on improving quality grade. The car-
cass marbling (Marb) EPD, which is influenced by carcass marbling
scores and ultrasound percent intramuscular fat (% IMF) measure-
ments, contribute to $QG.
Yield Grade ($YG)
$YG represents the yield grade segment of the
economic advantage found in $G. $YG is intended for the specialized
user wanting to place more emphasis on red meat yield. It provides a
multi-trait approach to encompass ribeye, fat thickness and weight into
an economic value for red meat yield.
$G combines both $QG and $YG, and may be the best carcass decision
tool for focusing on quality and red meat yield simultaneously.
Beef Value ($B)
, an index value expressed in dollars per head, is the
expected average difference in future progeny performance for post-
weaning and carcass value compared to progeny of other sires.
American Angus Association
®
Selection Tools
07/08
