2000 Across Breed EPD Adjustments
Livestock Update, August 2000
Scott Greiner, Extension Animal Scientist, Beef, Virginia Tech
The table of adjustment factors to estimate across-breed expected progeny differences for various beef cattle breeds was released at the Beef Improvement Federation Annual Meeting in Wichita, Kansas, on July 14. By using the across breed adjustment factors, animals of different breeds can be compared on the same EPD scale. The adjustment factors are based on comparative studies of the breeds conducted at the U.S. Meat Animal Research Center in Clay Center, Nebraska.
To calculate across breed EPDs, simply add the adjustment factor found in the table to the existing within-breed EPD for the animals of interest. For example, consider a Simmental bull with a WW EPD of +35 and a Charolais bull with WW EPD of +15. Would we expect the progeny out of different breed of dam for these two bulls to weigh about the same? To fairly compare the WW EPDs of these two bulls of different breeds, the EPDs must first be adjusted using the across-breed table. Using the table, the Simmental bull would have an across-breed WW EPD of +60.4 (35 + 25.4 = 60.4) and the Charolais bull an across-breed WW EPD of +59.8 (15 + 44.8 = 59.8). In this example, we would expect progeny of the Simmental bull and Charolais bull to be very similar on the average for weaning weight (across breeds EPDs of 60.4 vs. 59.8, for only .6 pound difference). Across-breed EPDs may be calculated for the growth and maternal traits of any breed listed in the table.
Across-breed EPDs are most useful to commercial producers utilizing crossbreeding programs. They may be used to compare bulls of different breeds that are being used in the crossbreeding program for similar purposes (ie. milk production in Gelbvieh and Simmental, or calving ease in Angus and Hereford). They may also be useful in managing uniformity when breeds are rotated in a crossbreeding system to avoid large fluctuations in traits such as birth weight and milk.
2000 Adjustment Factors to Add to EPDs of Various Breeds
to Estimate Across-Breed EPDs
|Breed||Birth Wt.||Weaning Wt.||Yearling Wt.||Milk|