A tool that has been in beef producer’s toolboxes since the 1970s has been expected progeny differences (EPDs). EPDs are a tool producers can utilize when comparing bulls within each breed for example birth weight, weaning weight or yearling weight. EPDs across different breeds and database cannot be directly compared because of differences in the genetic base.
Since 1993, the U.S. Meat Animal Research Center (USMARC), a part of the USDA Agricultural Research Service, has produced a table of factors to adjust the EPDs of cattle so that the merit of individuals can be compared across breeds. The table allows producers to compare EPDs from multiple breeds can be compared by adding/subtracting the appropriate adjustment factors to the EPDs resulting from the most recent genetic evaluations for each of 18 breeds.
“The AB-EPDs are most useful to commercial producers purchasing bulls of more than one breed to use in crossbreeding programs,” says Larry Kuehn, USMARC. “For example, in terminal crossbreeding systems, AB-EPDs can identify bulls in different breeds with high growth potential or favorable carcass characteristics.”
Each year USMARC releases updated tables. The factors are derived by estimating breed differences from the USMARC germplasm evaluation program and adjusting these differences for the EPDs of the sires that were sampled in the system. Traits for which factors are estimated are birth weight, weaning weight, yearling weight, maternal weaning weight (milk), marbling score, ribeye area, backfat depth (fat), and carcass weight.
Kuehn says the yearling weight EPD adjustment factors are derived using a BIF-adjusted postweaning gain and weaning weight as separate traits which is consistent with most national cattle evaluations. Thus, these factors directly relate to EPDs from national cattle evaluations.
The adjustment factors in Table 1 were updated using EPDs from the most recent national cattle evaluations conducted by each of the 18 breed associations (current as of January 2026).
As an example, suppose a Red Angus bull has a carcass weight EPD of + 20.0 lb., and a Hereford bull has a carcass weight EPD of + 72.0 lb. The across-breed adjustment factors for carcass weight EPD (see Table 1) are -3.8 lb. for Red Angus and -68.2 lb. for Hereford. The AB-EPD is 20.0 lb. – 3.8 lb. = 16.2 lb. for the Red Angus bull and 72.0 lb. – 68.2 = 3.8 lb. for the Hereford bull. The expected carcass weight difference of offspring when both are mated to cows of another breed would be 16.2 lb. – 3.8 lb. = 12.4 lb.
Kuehn reminds producers it is important to note that the table factors (Table 1) do not represent a direct comparison among the different breeds because of base differences between the breeds.
“They should only be used to compare the EPDs (AB-EPDs) of animals in different breeds,” he says.
To reduce confusion, means on a EPD scale are presented in Table 2. The EPD scale, which is one half of the genetic effect, is used because they are the expected differences from using these animals as a sire. These means are also called ‘breed of sire means” meaning the effects expected from using average animals from each breed as a sire.
