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Title: ACROSS-BREED EPD TABLES ADJUSTED TO A 1995 BASE

Author
item Van Vleck, Lloyd
item Cundiff, Larry

Submitted to: Beef Improvement Federation Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 4/4/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary: Beginning in 1989, records from the Germ Plasm Utilization project at the USDA Meat Animal Research Center have provided the basis for factors which allow comparison of pairs of bulls of 12 different breeds. The factors are added to the expected progeny differences calculated by the breed associations. For example, a Salers bull can be compared with a Pinzgauer bull (or any pair of bulls of the 12 breeds) for calf birth weight, weanin weight, yearling weight, and mothering ability. Thus, herd owners are not limited to comparisons among bulls of a single breed. This report up-dates the adjustment factors to a base year for 12 breeds as has been done annually since 1991. The base year for this up-date is 1995.

Technical Abstract: Records of F1 and 3-way cross progeny of 12 breeds of sire and maternal grand sire are used to estimate differences among the breeds for birth, weaning and yearling weight, and maternal ability. The same records are used to estimate coefficients of regression for progeny performance at MARC on breed association EPDs are estimated. These regression coefficients are used to adjust the estimates of breed differences for the difference between breed average EPD for animals born in 1995 and the average EPD of bulls used at MARC that contribute to estimates of breed differences. The regression coefficients show the proportion of differences in EPD that is exhibited in their calves at MARC. From these adjusted breed differences, factors are calculated that can be added to breed association EPD to allow comparison of bulls of different breeds. This report details the calculations used for this annual update of the procedure first formalized in 1991. Changes for 1997 included 1) birth weights of 167 progeny of 12 Angus bulls, 27 progeny of 2 Brahman bulls, and 28 progeny of 2 Charolais bulls were added with corresponding increases in progeny with weaning and yearling weights, 2) weaning weights of 129 grandprogeny and 3 Hereford sires, of 307 grandprogeny and 28 Angus sires, and of 116 grandprogeny and 6 Brahman sires were added to the maternal analyses, and 3) average EPD of Brahman non-parents born in 1995 was used. Due to mis-communication, average EPD from the 1994 calculations were used in the 1996 update.