Author
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POWELL, REX |
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Submitted to: International Red Cattle Conference Proceedings
Publication Type: Proceedings Publication Acceptance Date: 9/15/1997 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: The goal of the International Bull Evaluation Service (INTERBULL) is to facilitate international comparison of dairy cattle. In 1991, the INTERBULL Centre was established in Uppsala, Sweden, to provide global bull evaluations. The first Centre evaluations were released in August 1994 for Ayrshire and Holstein bulls from Nordic countries. For the first large-scale INTERBULL evaluation released in February 1995, national bull evaluation and pedigree files were combined using a genetic correlation between countries of .995. August 1995 INTERBULL evaluations were the first with variable genetic correlations (.87 to .96) among countries. A significant change for February 1997 INTERBULL evaluations was the use of data only from bulls born after 1979 for Holsteins. Each country in INTERBULL determines what use to make of INTERBULL evaluations on that country's scale. Most countries accept INTERBULL evaluations as official for foreign bulls, but some limit that acceptance to bulls without a domestic evaluation of at least a specified reliability. Red cattle have not been included as a separate breed in INTERBULL evaluations. The diversity of a Red breed is a detriment for computation of international evaluations because many quite different strains of cattle are represented and selection goals are varied. Differences in genetic variation for yield traits between strains make properly combining data in an evaluation a difficult task. One approach is to include Red bulls that are essentially red Holsteins or have been selected for yield in the Holstein analysis for which the national evaluation can provide genetic estimates on a Holstein scale. INTERBULL evaluations are the best resource for assessing merit of bulls across countries. |
