Advertisement
Article| Volume 79, ISSUE 5, P900-906, May 1996

Download started.

Ok

Impact of Second-Country Data of Foreign Bulls on International Evaluations of Dairy Bulls

      This paper is only available as a PDF. To read, Please Download here.

      Abstract

      Second-country data of foreign bulls are a primary source of information for international genetic comparison of dairy sires. Potential problems exist with this data, because imported semen is expensive, and progeny may receive preferential treatment. The extent of potential bias in international sire evaluations from inclusion of second-country data of imported bulls was examined using data from 25,205 Holstein bulls evaluated in the US, Canada, Italy, Holland, and Germany. Mean changes in international evaluations of potential candidates for export from inclusion of second-country data were <50 kg EBV for milk and <3 kg EBV for fat and protein, and changes in the international evaluations of imported bulls were <100 kg EBV for milk and <3 kg EBV for fat and protein. These changes suggest that bias from preferential treatment of progeny of foreign sires was not a significant problem for the countries examined. Application of reduced weight to second-country data of foreign sires can further reduce the chance of bias from preferential treatment. Based on this study, inclusion of second-country data of foreign bulls in international sire evaluations is appropriate, and problems due to preferential treatment are few.

      Key words

      Abbreviation key:

      ACD (evaluation based on all data), FCD (evaluation based on first-country data only), INTERBULL (International Bull Evaluation Service), MACE (multiple across country evaluation), PT (preferential treatment), R80 (evaluation based on limiting SCD to 80% reliability), R90 (evaluation based on limiting SCD to 90% reliability), SCD (second-country data)

      References

        • Banos G.
        Application of international sire evaluations.
        J. Dairy Sci. 1995; 78 (Abstr.): 221
      1. Banos, G., J. Philipsson, B. Bonaiti, M. Carabano, J. Claus, P. Leroy, P. Rozzi, G. Swanson, and J. Wilmink. 1993. Report of a joint research project between INTERBULL and COPA/COGECA on the feasibility of a simultaneous genetic evaluation of Black-and-White dairy bulls across the European Community countries. INTERBULL Bull. No. 9. Int. Bull Eval. Serv., Uppsala, Sweden.

        • Banos G.
        • Schaeffer L.R.
        • Burnside E.B.
        Genetic relationships and linear model comparisons between United States and Canadian Ayrshire and Jersey populations.
        J. Dairy Sci. 1991; 74: 1060
      2. Bonaiti, B., D. Boichard, A. Barbat, and S. Mattalia. 1993. Problems arising with genetic trend estimation in dairy cattle. Page 63 in Proc. INTERBULL Annu. Mtg., Aarhus, Denmark. INTERBULL Bull. No. 8. Int. Bull Eval. Serv., Uppsala, Sweden.

        • Goddard M.E.
        A method of comparing sires evaluated in different countries.
        Livest. Prod. Sci. 1985; 13: 321
        • Goddard M.E.
        Use of international data in national genetic evaluations.
        J. Dairy Sci. 1995; 78 (Abstr.): 222
      3. Mattalia, S. and B. Bonaiti. 1993. Use of full sib families to estimate the ‘a’ coefficients of conversion formulas between countries. Page 73 in Proc. INTERBULL Annu. Mtg., Aarhus, Denmark. INTERBULL Bull. No. 8. Int. Bull Eval. Serv., Uppsala, Sweden.

        • Powell R.L.
        • Wiggans G.R.
        • VanRaden P.M.
        Factors affecting calculation and use of conversion equations for genetic merit of dairy bulls.
        J. Dairy Sci. 1994; 77: 2679
        • Schaeffer L.R.
        Model for international evaluation of dairy sires.
        Livest. Prod. Sci. 1985; 12: 105
        • Schaeffer L.R.
        Multiple-country comparison of dairy sires.
        J. Dairy Sci. 1994; 77: 2671
        • Schaeffer L.R.
        • Reents R.
        • Jamrozik J.
        Factors influencing international comparisons of dairy sires.
        J. Dairy Sci. 1995; 78 (Abstr.): 221
      4. Weigel, K. A., and T. J. Lawlor, Jr. 1994. MACE for total conformation score of Holstein bulls from the Netherlands and the United States. Page 146 in Proc. INTERBULL Annu. Mtg., Ottawa, ON, Canada. INTERBULL Bull. No. 10. Int. Bull Eval. Serv., Uppsala, Sweden.

        • Wilmink J.B.M.
        • Meijering A.
        • Engel B.
        Conversions of breeding values for milk from different populations.
        Livest. Prod. Sci. 1986; 14: 223