After lactation yield, length of productive life is the second most important trait in dairy production (Allaire and Gibson, 1992). A long productive life of a cow helps to reduce replacement costs, and the full milking potential is only attained in later lactations (Essl, 1982). Ducrocq (1987) distinguishes between culling caused by poor lactation production and culling that is due to fitness problems. In cattle breeding the functional length of productive life (fLPL) is of interest. The fLPL is independent of production and other effects having a systematic influence on length of productive life. In Austria breeding values for fLPL have been routinely estimated for bulls and cows since 1995 (Fuerst and Sölkner, 1997) using survival analysis. Currently Germany and Austria are working on the implementation of a joint breeding value estimation for all traits. Implementation should be finalised by November 2002. Breeding values for longevity have been estimated jointly since November 2001. Compared to the former Austrian evaluation the model for survival analysis was changed from the Cox model to the Weibull model, which allows inclusion of time-dependent effects. The objective of this paper is to present the joint routine genetic evaluation using survival analysis for Simmental in Austria and Germany.
Proceedings of the World Congress on Genetics Applied to Livestock Production, Volume 2002. Session 1, , 1.16, 2002
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