Submitted to: American Dairy Science Association Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 7/27/1998
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: The ability of national and international evaluations to predict later national evaluations for milk, fat, and protein yields was compared for Holstein bulls evaluated in Canada, Germany, Italy, The Netherlands, and the US. Data included national (N95) evaluations that were input data for Feb. 1995 International Bull Evaluation Service (INTERBULL) evaluations, Feb. 1995 INTERBULL (I95) evaluations on each country's scale recalculated using Aug. 1997 methodology, and recent 1997 national (N97) evaluations. A bull was included only if the I95 evaluation included daughter information from at least one country besides the country for the national evaluation. If use of foreign data is beneficial, I95 evaluations should be closer to N97 evaluations than are N95 evaluations. Strong part-whole relationships were recognized between N95 and N97 evaluations and between N95 and I95 evaluations. Therefore, results only for bulls with the largest increases in national and foreign daughter data relative to N95 evaluations were reported. Correlations between I95 and N97 evaluations were higher than between N95 and N97 evaluations by .01 to .04 except for the US. For the US, correlations with N97 evaluations were lower for I95 evaluations than for N95 evaluations by .01 for milk and protein yields and the same for fat yield. Standard deviations (SD) of differences of N97 evaluations from N95 and I95 evaluations showed better agreement for I95 evaluations than for N95 evaluations except for US milk yield. Nearly all bulls originated from North America, particularly in the US, and reduction in SD of evaluation differences was less for Canada and the US than for European countries. Including foreign data generally improved prediction of later national evaluations, with the benefit greatest for importing countries.