Submitted to: AIPL Research Reports
Publication Type: Government Publication
Publication Acceptance Date: April 23, 1999
Publication Date: N/A
Technical Abstract:
Current and planned changes by the Animal Improvement Programs Laboratory (AIPL) to USDA-DHIA genetic evaluations in May 1999 were documented. To prevent selection bias, a test day early in lactation is required. Because the best prediction method is used to calculate lactation records, the requirement for first test day has been relaxed from 75 to 90 days in milk (DIM). Test-day data stored by AIPL were found to be incomplete, and the requirement for first test day was eased further to 150 DIM for calvings before September 1998. Even with this additional requirement relaxation, some lactation records previously included in evaluations were excluded in May 1999, which resulted in a slight decrease in the number of daughters for some bulls. Foreign evaluations of bull dams from Australia, Denmark, Germany, Italy, and New Zealand were used to update bull parent average along with those from Canada, France and The Netherlands, which had contributed evaluations previously; of the 725 dam evaluations included, Canada provided the most. Fields for economic indexes of fluid merit dollars (FM$) and cheese merit dollars (CM$) and inbreeding of future progeny are now available for cow evaluations in format 105. The FM$ and CM$ indexes are calculated the same for cows as for bulls except that productive life for Holstein bulls is adjusted for correlated type traits. The average relationship of a cow or a bull to its breed is calculated from the same sample of 600 females for that breed so that expected inbreeding is defined the same regardless of gender. The U.S.-Interbull bull evaluation format 031 will be expanded to include identification of the maternal grandsire and the bull's full birth date in place of a 2-digit year. The new format will be used for August 1999 evaluations.
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