2007 Beef Sire Directory
Using EPDs is the fastest way to genetically improve beef cattle. Breed
associations collect vast amounts of data on various traits in order to document
the genetic potential of cattle. The accuracy and power of this data is tremendous.
Armed with Sire Summary data, you can make your breeding decisions
based on documented records for a variety of traits and breed cattle that work
in your individual program. The Sire Summaries calulate EPDs (Expected
Progeny Differences) for the following traits:
Calving Ease
Birth Weight
Weaning Weight
Yearling Weight
Maternal Milk
Maternal Weaning Weight
Carcass Traits
Ultrasound Traits
Scrotal Circumference
Yearling Height
Gestation Length
Stayability
Feedlot Value
Grid Value
Beef Value
Weaned Calf Value
Cow Efficiency
Performance information used to calculate EPD values can come from any
combination of the following:
- Progeny
- Relatives in the pedigree (particularly sire and dam)
- Grand progeny
- The individual’s own performance record
- Genetic correlation of traits
As an individual bull obtains progeny records, the accuracy of the EPD
increases and becomes more reliable. Breeders need to remember that EPD values
are not exact and actual progeny differences will vary from the predicted
EPD values. Therefore, breeders should use proven bulls with high accuracies
more heavily than young bulls with low accuracies.
Sample Evaluation Report
EPD - Expected Progeny Difference - The expected difference in performance
of a bull’s progeny compared to the average progeny performance of all
bulls evaluated. Use EPDs to compare sires of the same breed, not to predict
actual weights. EPDs are breed specific and cannot be used to compare sires
across breeds.
Acc. - Accuracy - A measure of reliability regarding the genetic merit of a
bull. Higher accuracy means the data is more reliable and will change less with
additional progeny.
% Rank - Based on percentages, this indicates where a bull’s EPD for a
particular trait ranks him in his respective breed.
CED or CE - Calving Ease Direct 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.
BW - Birth Weight EPD predicts the difference in average birth weight of a
bull’s calves compared to calves of all other bulls evaluated. Reported in
pounds.
WW - Weaning Weight EPD predicts the difference in average 205 day
adjusted weight of a bull’s calves compared to calves of all other bulls evaluated.
Reported in pounds.
YW - Yearling Weight EPD predicts the difference in average 365 day
weight of a bull’s progeny compared to progeny of all other bulls evaluated.
Reported in pounds.
YH - Yearling Height (Angus) - The EPD predicts the difference in hip
height of a bull’s progeny at yearling compared to progeny of all other bulls
evaluated. Reported in inches.
SC - Scrotal Circumference - The EPD predicts the difference in scrotal circumference
of a bull’s male offspring at yearling compared to progeny of all
other bulls evaluated. Reported in centimeters.
CEM or MCE - Calving Ease Maternal 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.
Milk - The millking ability of a bull’s daughters. The EPD predicts the difference
(due to milking ability) in average 205 day weight of a bull’s daughters’
calves compared to the calves from daughters of all other bulls evaluated.
Reported in pounds.
MWW - Maternal Weaning Weight (Simmental); M&G - Milk and Growth
(Hereford); TM - Total Maternal (Red Angus) - The Weaning Weight of a bull’s
daughters’ calves. This figure reflects both the milking ability of a bull’s daughters
and the growth potential of their calves. Reported in pounds.
$EN - Cow Energy Value, 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.
Stay - Stayability - The EPD predicts the probability of a bull’s daughters
staying in production to at least six years of age compared to daughters of all
other bulls evaluated. A higher value indicates increased stayability.
Carcass Traits
CW - Carcass Weight - The EPD predicts the difference in hot carcass
weight of a bull’s progeny compared to progeny of all other bulls evaluated at
a given endpoint. Reported in pounds.
Marb - Marbling - The EPD is an expression, as a fraction, of the difference
in the average USDA marbling score of a bull’s progeny compared to progeny
of all other bulls evaluated at a given end point. The higher the value, the higher
the marbling score.
REA - Ribeye Area - A measure of the muscle in the carcass. The EPD predicts
the difference in ribeye area of a bull’s progeny compared to the progeny
of all other bulls evaluated. Reported in square inches.
Fat - The EPD predicts the difference in fat thickness, measured between
the 12th and 13th ribs, of a bull’s progeny compared to progeny of all other
bulls evaluated. Reported in inches.
Ultrasound Traits - The use of ultrasound technology to evaluate the carcass
merit of live animals has become widely accepted by several breed associations.
This tool allows the prediction of accurate genetic values for carcass traits
with less time and less expense than traditional carcass evaluation. Ultrasound
measurements are adjusted to an age-constant endpoint.
IMF - Percent Intramuscular Fat - The EPD predicts the percentage of intramuscular
fat in the ribeye, which is directly related to USDA Marbling Score.
Higher IMF values indicated a higher % intramuscular fat, therefore a higher
marbling score.
REA - Ribeye Area - see REA under Carcass Traits above.
FT - Fat Thickness - The EPD predicts the external fat thickness at the 12th
rib of a bull’s progeny compared to progeny of all other bulls evaluated. It is a
weighted average of 60% of the rib fat scan and 40% of the rump fat scan.
Reported in inches.
Additional Terms
Homozygous Polled - This individual is polled and carries two polled
genes. The animal will sire all polled offspring regardless of whether the other
parent is horned or polled.
Heterozygous Polled - The individual is polled but carries both a polled
gene and a horned gene. The animal will sire both polled and horned calves.
Homozygous Black - This individual will always pass on a black gene for
color to his offspring. When bred to a diluted cow, this bull can still sire gray
color patterns.
Nondiluter - This individual does not carry the diluter gene and therefore
will not pass on the diluter gene to his progeny.
$Value Indexes (Angus)
Weaned Calf Value ($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 ($G), an index value expressed in dollars per head, is the
expected average difference in future progeny performance for carcass grid
merit compared to progeny of other sires.
Beef Value ($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.
Indexes (Simmental)
All-Purpose Index (API), evaluates sires being used on the entire
cowherd (bred to both Angus first-calf heifers and mature cows) with a portion
of their daughters being retained for breeding and the steers and remaining
heifers being put on feed and sold grade and yield. All EPDs, except tenderness,
are used in this index.
Terminal Index (TI), evaluates the economic merit of sires where they
are bred to mature Angus cows and all offspring are fed and sold grade and
yield. Consequently, maternal traits such as milk, stayability and MCE are
not considered in this index.
Both API and TI are expressed in net dollars returned per cow exposed.
$Profit Indexes (Hereford)
Brahman Influence Index (BII), is a maternally-focused index based on
using Hereford bulls on Brahman x Hereford cows. Emphasis is placed on
fertility, REA and IMF, with progeny harvested through a commodity market.
Baldy Maternal Index (BMI), is a maternally-focused index based on
using Hereford bulls on Hereford x Angus cows with a progeny endpoint
directed towards CHB. Emphasis is placed on fertility, CE, WW, IMF and
REA with a slight negative pressure applied to yearling weight to keep the
mature size of cattle manageable.
Certified Hereford Beef (CHB), is a terminal sire index based on using
Hereford bulls to sire calves for the CHB market. Some emphasis is applied
to CE with positive pressure applied to WW and YW, IMF and REA. No
emphasis is placed on fertility as all calves are harvested.
Calving EZ (CEZ), is a general purpose index that focuses on bulls that
can be bred to heifers with resulting calves marketed through CHB. CE and
MCE carry significant weight along with fertility. Little emphasis is placed
on growth with less on carcass. This index is specifically designed to be
used in a heifer program.
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