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Title: CHANGES IN USDA-DHIA GENETIC EVALUATIONS (JANUARY 1996)

Author
item Vanraden, Paul
item Powell, Rex
item Wiggans, George
item Norman, H

Submitted to: AIPL Research Reports
Publication Type: Government Publication
Publication Acceptance Date: 1/19/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary: Changes in USDA-DHIA genetic evaluations in January 1996 were documented so that the dairy industry could make most effective use of distributed information. Productive life (PL) and somatic cell score (SCS) evaluations and net merit indexes (NM$) are now computed for all cows. Breeders who have switched to NM$ for bull selection now also can choose the best cows based on NM$. Summary tables of means and standard deviations that accompany the evaluation list for bulls in active artificial-insemination service were restructured. Means and standard deviations for PL, SCS, and NM$ now are included in the summary tables. This information should be much more useful because of program improvements to include more complete data. International Bull Evaluation Service (INTERBULL) evaluations will be released on February 25, and INTERBULL evaluations on the U.S. scale are official for any bull that doesn't have a USDA evaluation. If a bull has neither a USDA nor an INTERBULL evaluation, conversion is still needed, and reliability of the converted evaluation now considers the square of the genetic correlation between the U.S. and the other country. Bull evaluations were sent by USDA to Canada before the general U.S. release date for use in Canada's multitrait across-country evaluation. Canada released evaluations early for Canadian dams of U.S. bulls; more weight now is given to information from these dams. Information on new Canadian traits (SCS, herdlife, and a total economic value analogous to NM$) won't be included in USDA bull evaluations because conversion formulas aren't yet available. Cooperation with Canada may allow earlier availability in Canada of evaluations for U.S. bulls and act as a model for rapid data exchange within INTERBULL.

Technical Abstract: Changes in USDA-DHIA genetic evaluations in January 1996 were documented. Productive life (PL) and somatic cell score (SCS) evaluations and net merit indexes (NM$) are now computed for all cows; formerly, PL and NM$ were released only for cows 3 years of age or older. Summary tables of means and standard deviations that accompany the evaluation list for bulls in active artificial-insemination (AI) service were restructured. Means and standard deviations for PL, SCS, and NM$ now are included in the summary tables. The format of the active AI bull list has been changed to include these new traits directly. The complete evaluation list on microfiche uses this same new format and includes the new traits for the first time. International Bull Evaluation Service (INTERBULL) evaluations will be released on February 25, and INTERBULL evaluations on the U.S. scale are official for any bull that doesn't have a USDA evaluation. If a bull has neither a USDA nor an INTERBULL evaluation, conversion is still needed, and reliability of the converted evaluation now considers the square of the genetic correlation between the U.S. and the other country. Values for these correlations are provided by INTERBULL and range from .87 to .96. Bull evaluations were sent by USDA to Canada before the general U.S. release date for use in Canada's multitrait across-country evaluation. Canada released evaluations early for Canadian dams of U.S. bulls; more weight now is given to information from these dams by considering feedback occurring in simultaneous animal model solutions. Information on new Canadian traits (SCS, herdlife, and a total economic value analogous to NM$) won't be included in USDA bull evaluations because conversion formulas aren't yet available.