Author
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Powell, Rex |
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Submitted to: Holstein World
Publication Type: Trade Journal Publication Acceptance Date: 4/5/1995 Publication Date: N/A Citation: N/A Interpretive Summary: The goal of the International Bull Evaluation Service (INTERBULL) is to facilitate the genetic comparison of dairy cattle among countries. February 1995 marked the first official release of INTERBULL evaluations on a large scale. Now five breeds are analyzed, and data from nine countries were included for Holsteins (54,781 bulls). All bulls received evaluations on the scale for each of the nine countries through use of the relatively new procedure called MACE (short for Multitrait, Across Country Evaluation). With MACE, thousands of bulls contribute to the results, which should be more accurate and more stable. To determine how U.S. bulls rank internationally, distribution of the top bulls was determined according to trait. United States representation was highest for milk and higher for dollar value of milk, fat, and protein than for protein. Even with the most extreme economic weighting (substantial negative emphasis on milk volume), the U.S. still had about half of the top 100 bulls. The INTERBULL evaluations represent a new chapter in genetic information, one that is truly international, and comparison of U.S. and foreign bulls will allow U.S. breeders to select the best germplasm and to remain competitive worldwide. Technical Abstract: The goal of the International Bull Evaluation Service (INTERBULL) is to facilitate genetic comparison of dairy cattle among countries. February 1995 marked the first official release of INTERBULL evaluations on a large scale. Five breeds were analyzed, and data from nine countries were included for Holsteins (54,781 bulls). All bulls received evaluations on the scale for each of the nine countries through use of MACE (Multitrait, Across Country Evaluation), which treats various national evaluations as separate but related traits. With MACE, thousands of bulls contribute to the results, which should be more accurate and more stable. Progeny- tested bulls with common sires and maternal grandsires provide the links from one country's scale to another. To determine how U.S. bulls rank internationally, distribution of the top bulls was determined according to trait. United States representation was highest for milk and higher for dollar value of milk, fat, and protein than for protein. Even with substantial negative emphasis on milk volume, the U.S. still had about half of the top 100 bulls. The unofficial INTERBULL evaluations for U.S. bulls with no data from other countries included were usually exactly the same as USDA evaluations for fat and protein yields and just a few pounds different for milk yield. Because genetic correlations among countries are assumed to be nearly perfect (.99), foreign bulls may rank higher than they would if the true correlation was lower and had been used. Investigations have begun to determine more appropriate genetic correlations and to see if more evaluations from bulls previously evaluated in another country can be used. |
