The Base is Set

Part 5 of a Series

The ASA Board of Trustees has made a decision regarding the base for the MBE Genetic Evaluation to implemented in June, 1997 for the Fall 1997 Sire Summary. They considered several different options for defining the base using the estimated gene effects from the MBE analysis: 1) Average Angus genes in 1991; 2) Average of Simmental, Angus, Hereford, and Brahman genes in 1991; 3) Average British genes in 1991; 4) 1986 Purebred Simmental; and 5) Average of twelve gene effects in 1991. The base chosen by the Board for the weight traits is the average Simmental, Angus, Hereford, and Brahman genes in 1991.

In table 1, the average EPDs for purebred Simbrah and Simmental calves born in 1996 are listed for the Spring '97 evaluation and the MBE Research Run using the current 1986 base and the base approved by the ASA Board. For Simmental breeders, the MBE EPDs will be higher for all traits compared to the PBE EPDs. Breeders can anticipate a 3 lb. increase in BWT EPD, 19 lb. increase in WWT EPD, 35 lb. increase in YWT EPD, 8 lb. increase in MMK EPD, and 21 lb. increase in MWW EPD due to setting the base using the average of Simmental, Angus, Hereford, and Brahman genes in 1991.

Why the 1991 Four Breed Base?

1. The EPDs more accurately epresent the merit of Simmental cattle than the current 1986 base.
2. Many commercial cattle are British x Continental or British x Brahman and the EPDs produced will give a good approximation of the results to be expected by breeding to seedstock with the genetic make-ups.
3. The resulting milk EPDs will appropriately de-emphasize breeders and customers' concentration and consternation with our current distribution of maternal milk EPDs.
4. This base provides a blend of our strengths (growth and milk) coupled with adequate emphasis on traits creating challenges (birth weight).
5. The base is the average of the estimated gene effects for the four breeds having the greatest influence in the ASA data set.

During the last two months, the ASA and CSA Boards approved the combining of the U. S. and Canadian data files into a single North American evaluation. The final research run with the MBE system is being performed using the combined data from the American Simmental and the Canadian Simmental Association. Once this research run is completed, we will have the final look at the planned changes to the EPD system prior to the Fall '97 evaluation.