Page
v
Carcass Weight EPD (CWT): expressed in pounds, is a predictor of the difference in hot carcass weight of
progeny.
Carcass Backfat EPD (BF): expressed in inches, is a predictor of the difference in 12
th
rib backfat of progeny at a
given end point.
Carcass Ribeye Area EPD (REA): expressed in square inches, is a predictor of the difference in ribeye area of
progeny at a given end point.
Carcass Marbling Score EPD (MARB): The marbling score EPD can be used to select sires that will produce
progeny with more marbling at a constant fat or age endpoint. The higher the marbling score EPD, the higher
the amount of intramuscular fat in the ribeye muscle. The genetic correlation between marbling score and
external fat at the 12
th
rib is nearly zero. This means breeders can select for increased marbling and will not
have to worry about selecting for increased external fat. Intramuscular marbling contributes to the overall
eating experience of beef. It is a significant component of juiciness and flavor of the beef product.
Intramuscular fat plays a small role in tenderness of beef.
Stayability (STAY): Expressed as the probability that an animal’s daughters will remain in production to at least
six years of age when compared to the daughters of another animal. A measure of sustained fertility that
probably reflects traits such as fleshing ability and structural soundness.
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 comparison with another sire’s
calves. In herds where temperament problems are not an issue, this expected difference would not be
realized.
$ Values and Index Values
$ Value and Index Value EPD values are a way of combining several EPDs together to come up with 1
value for a producer to look at. The individual EPD values are weighted according to importance through
statistical methods based on industry market pressures and expressed in dollars. Below are the definitions of
the values seen in the catalog:
$EN
“Cow Energy Value”, assess differences in cow energy requirements, expressed in dollars per cow per
year, as an expected dollar savings difference in future 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. (Angus only)
$W
“Weaned Calf Value”, an index value expressed in dollars per head, is the expected average difference
in future progeny performance for pre‐weaning merit.
$W
includes both revenue and cost adjustments
associated with differences in birth weight, weaning direct growth, maternal milk, and mature cow size. Useful
for producers selling calves at weaning. (Angus only)
$F
“Feedlot Value”, 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. (Angus only)
$B
“Beef Value”, 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. (Angus only)
API
“All Purpose Index”, an index value expressed in dollars per head, 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.
(Simmental only)
TI
“Total Index”, an index value expressed in dollars per head, evaluates sire for use on mature Angus
cows with all offspring put on feed and sold grade and yield. (Simmental only)
