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Beef Management Tips:
1999 Across Breed EPD Adjustments
Livestock Update, July 1999
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 Roanoke, Va., on June 17. 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, Neb.
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 Hereford and a Simmental bull who both have a Weaning Weight EPD of +30. 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 Hereford bull would have an across-breed WW EPD of +32 (30 + 2 = 32) and the Gelbvieh bull an across-breed WW EPD of +50 (30 + 20 = 50). In this example, we would expect progeny of the Gelbvieh bull to weigh 18 pounds more on the average at weaning than progeny of the Hereford bull (across breeds EPDs of 50 vs. 32). 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. For example, comparing bulls of different breeds that are being used in the system to add milk and growth. 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.
1999 Adjustment Factors to Add to EPDs of Various Breeds to Estimate Across-Breed EPDs
| Breed | Birth Wt. | Weaning Wt. | Yearling Wt. | Milk |
| Angus | 0 | 0 | 0 | 0 |
| Brahman | 14.4 | 36 | -3 | 28 |
| Charolais | 11.5 | 43 | 70 | 2 |
| Gelbvieh | 8.0 | 20 | 10 | 11 |
| Hereford | 4.3 | 2 | -4 | -9 |
| Limousin | 8.4 | 33 | 36 | -6 |
| Maine Anjou | 12.6 | 40 | 59 | 26 |
| Pinzgauer | 9.2 | 30 | 34 | 7 |
| Salers | 6.4 | 33 | 45 | 19 |
| Shorthorn | 8.6 | 31 | 48 | 11 |
| Simmental | 7.1 | 18 | 50 | 18 |
| South Devon | 8.1 | 20 | 37 | 9 |
| Tarentaise | 5.4 | 31 | 22 | 19 |