- Adj. 205 Wt.
- This is the adjusted 205 day weight gain determined by calculating the
weight gain per day between the birth date and the date the animal was weighed
and then using that to determine what the animal would have weighed 205 days after
- Adj. Year Wt.
- This is the adjusted 365 day weight gain determined by calculating the
weight gain per day between the birth date and the date the animal was weighed
and then using that to determine what the animal would have weighed 365 days after
EPD - Expected Progeny Differential
From the American Hereford Association, Understanding EPDS
- CED EPD
- CED (Calving Ease-Direct): A positive number or higher number for
this EPD indicates easier calving ease. The CED EPD predicts the ease
with which the progeny of the individual should be bom. This EPD is
derived from the calving ease scores turned in. with birth weight for the
animals in the pedigree being a major part of this formula. Consider
selecting for either CE or BW, not both, because doing both over-
- BW EPD
- BW (Birth Weight): Derived from the actual birth weight ranking
within the contemporary group where the calf was born. The first BW
EPD issued for a calf is the average of the dam and the sire. with an
adjustment made from that number to reflect the actual birth weight of an
individual as compared to its contemporary group average. An actual birth
weight that is exceptionally higher or lower than the average of its
contemporary group will change that individual's BW EPD accordingly.
The BW EPD is primarily changed when progeny have been recorded
from the subject animal and the accuracy becomes much higher. The birth
weight is adjusted according to the age of dam. The BW EPD has no
correlation to an actual birth weight (an 85 Ib. calf can have a BW EPD of
4.5 or 5.5 or 6.5 or even a 2.5 in different herds). A lower number is
desirable and indicates less expected birth weight.
- WW EPD
- WW (Weaning Weight): An EPD to measure the growth genetics up
to weaning age (205 days). This growth EPD is derived from the weaning
weights turned in for contemporary groups. This EPD is generally very
indicative of the growth up to weaning age, based on the genetic history
of the animals in the pedigree. Actual weaning weights are adjusted for the
age of dam. Weaning weights have been taken and recorded more than
most any other EPD trait. The accuracy is important to the possible
changes of this and all EPDs. The WW EPD has a significant effect on
YW EPD, as well.
- MM EPD
- MM (Maternal Milk): An EPD derived from weaning weight to
measure the milking ability of the individual. MM is that part of WW due
to a dam's milking ability. A proven bull's milk EPD is derived nearly
100% from his daughters in production. When a bull is born, his MM EPD
is the average of his sire and dam. The EPD has low accuracy and will
change according to how his sire or dam may change. When his daughters
go into production, the way they produce in their contemporary groups,
either by being above average or below average, will change the sire's
MM EPD accordingly. At this point the accuracy will go up, which gives
a truer picture of the bull's actual ability to genetically pass milk to his
progeny. A proven cow's milk EPD is derived from her own production
and her daughters in production. A cow's own production contributes to
less than 50% of her own MM EPD. Her daughters in production
contribute over 50% to her own MM EPD. The MM EPD has much more
meaning for bulls and cows old enough to have daughters in production.
- YW EPD
- YW (Yearling Weight): An EPD to measure the growth from
weaning age to yearling age. The YW EPD is tied to the WW EPD; the
growth of the individual through yearling is effected by weaning weight.
This EPD will be fairly indicative of the genetics in the pedigree as we in
the industry have taken weaning and yearling weights as actual
measurements longer than many traits measured and with fewer
adjustments. The accuracy is important to the YW EPD as to the amount
of possible fluctuation that may occur.
- M&G EPD
- M&G (Maternal Milk & Growth): This EPD is part of WW plus MM
= M&G. This EPD is sometimes referred to as Total Maternal or
Combined Maternal. This is an EPD that reflects the combined WW and
MM EPD. It reflects the growth to weaning age plus the milk production
to weaning time. It is an estimate of daughters' progeny weaning weight.
- SC EPD
- SC (Scrotal Circumference): The SC EPD is the best predictor of
fertility and is also associated with the age of puberty. The higher number
at a younger age may indicate earlier puberty. SC is measured in
centimeters. The SC EPD is adjusted to 365 days. In this genetic analysis
theory, a multiple trait mode! was used for SC. WW and YW EPD were
used as the predictor variable to increase the accuracy of SC EPD.
- CEM (Maternal Calving Ease); This EPD indicates the ability of a
sire's daughters to have a calf at two years of age. Higher or positive
numbers meaning easier calving for the daughter of the individual. Some
of the factors that determine CEM are birth weight, calving ease and
growth of the daughters.
- REA EPD
- REA (Ribeye Area): This EPD is derived from ultrasound
measurements of live cattle at a year and adjusted to 365 days of age. The
REA EPD is measured in square inches, reflecting the area of the ribeye.
Cattle with a higher REA EPD are expected to produce progeny that have
higher red meat yield at harvest time. The carcass weight also reflects the
yield at harvest time. The more animals that data is collected from on a
sire, the more accurate the EPD.
- FAT EPD
- FAT (Rib Fat): Animals with low or negative FAT EPDs are expected
to produce leaner progeny then those with higher FAT EPDs. This EPD
measures fat thickness at the twelfth rib through ultrasound measurements
at a year of age on live animals. These measurements have been shown to
be highly correlated to actual back fat at harvest. All data is done through
ultrasound scale. The more animals that data is collected from on a sire,
the more accurate the EPD will be.
- IMF EPD
- IMF (Intramuscular rat): This EPD is derived from the ultrasound
measurement of the intramuscular tat in the ribeye, sometimes called
marbling. Marbling is a term generally used on fat steers at harvest time.
The data is collected on yearling bulls and adjusted to 365 days, a time
period that on a bull correlates to fat steers at harvest. This EPD is read
with the higher number indicating the progeny will have a higher quality
grade at harvest.
- BMI$ Index
- BMI$ (Baltly Maternal Index): This index is for the commercial
cow calf producer to maximize profit when Hereford bulls are used on
British cross cows in a rotational crossbreeding program. This index
assumes that the producer raises his own replacements and is retaining
ownership of the balance of the calf crop through harvest, selling on a
CHB grid. This index is an efficiency index that has a negative effect on
too much milk. High milk will result in lower reproductive efficiency and
require more nutrition for the cows. The CEM and CED are also used in
this index, as live calves and less calving difficulty lead to increased
fertility. This index also puts positive weight on WW and negative Weight
on YW. This adds to the efficiency value of Hereford-sired cattle for the
commercial cow calf producer
- BH$ Index
- BHS (Brahman Influence Index): This index is similar to the
BMI$, with the primary difference being Hereford bulls are used in a
rotational crossbreeding program on Brahman influenced cows rather than
British cows. This index places more importance on fertility and the age
of puberty, and less importance on growth and calving ease. This index
has been designed to place more importance on traits where Brahman
cattle may be more deficient.
- CEZ$ Index
- CEZ$ (Calving EZ Index): This index is similar to the BMI$. This
index is to measure efficiency and dollar value in the progeny of a
Hereford bull when used by a commercial cow call producer to breed
yearling heifers. Compared to other indexes, the emphasis has been put on
Calving Ease Direct and Calving Ease Maternal.
- CHB$ Index
- CHB$ (Certilied Hereford Beef Index): This is a terminal sire
index. This index represents Hereford bulls used on British cross cows
with all progeny sold as retained ownership on a CHB grid. This index put
emphasis on growth and all areas of carcass values.
Herd Sires |
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