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Hereford BII$ is Brahman Influence Index. This is similar to BMI$, except that the bulls are
mated to Brahman-based cows. It puts more emphasis on fertility and age at puberty, and less on
growth and calving ease.
Hereford CHB$ is Certified Hereford Beef Index. This is the expected average performance of
progeny of Hereford bulls mated to British-cross cows, with all progeny sold as fed cattle on a
Certified Hereford Beef LLC pricing grid. It is a terminal sire index, including growth and
carcass information only, since all progeny are marketed and no females are retained in the herd.
Limousin $MTI is Mainstream Terminal Index. This is the expected average profit per carcass of
progeny of Limousin bulls mated to British-cross cows, with all calves placed in the feedlot and
sold on a mainstream grid. It is a terminal sire index, including growth and carcass information
only, since all calves are marketed and no females are retained in the herd.
Simmental and SimAngus API is All-Purpose Index. This is the expected average performance
of progeny of Simmental bulls used on the entire Angus cowherd, with a portion of the daughters
being retained for breeding and the remaining progeny being put on feed and sold grade and
yield.
Simmental and SimAngus TI is Terminal Index. This is the expected average performance of
progeny of Simmental bulls mated to mature Angus cows, with all offspring placed in the feedlot
and sold grade and yield. It includes growth and carcass information only, since all progeny are
marketed.
Accuracy
Most EPDs are reported with an Accuracy (ACC) value, which ranges from 0 to 1. It is a
measure of the reliability of the EPD. EPDs will change and become more accurate as additional data on
the bull and his relatives are processed by the breed association. For most yearling bulls, ACC is low,
because they have not sired any progeny. Some breeds report the accuracy of these EPDs as BK, I, P,
P+, or PE. These indicate that the EPD is based on pedigree data, or is an interim EPD based on
pedigree data and the bull’s own performance.
Percentile Tables
Average EPDs for most traits are not zero. The actual average will be different for each breed.
Percentile tables must be used to determine where a bull’s EPDs and indexes rank within the breed.
EPDs and $ Indexes for the bulls in the IBEP test should be compared to percentiles for non-parent bulls
of the same breed. Look up the bull’s EPD in the table to determine where he ranks in his breed. For
example, an Angus bull with a Yearling Weight EPD of +90 lb. is in the top 35% of Angus non-parent
bulls. An Angus bull with a Birth Weight EPD of +1.0 lb. is in the top 30%. Remember that for most
traits, a positive EPD is desirable. However, for Birth Weight, Carcass Fat, Yield Grade, and Days to
Finish, a negative EPD is desirable.
The EPDs and $ Indexes in the sale catalog are reported with the bull’s percentile ranking in *’s.
These are in 10% groups. An EPD with *10* is in the top 1-10% of the non-parent bulls of the breed,
*9* is 11-20%, and so on; *2* is 81-90%, and *1* is 91-100% or the bottom 10%.
Percentile tables provided by the breed associations for breeds in the current IBEP test follow
this article. (Although Simmental, Red Angus, Chianina, Maine Anjou and Gelbvieh association EPDs
can be directly compared, percentile tables will be different for each breed.)
