Curtail high cull rates with productive life selection

摘要

GrENETIC evaluations for productive life first became available in 1994. Since then, we have placed greater emphasis on functional traits. The current NM$ index places 35 percent on the yield traits with 19 percent on fat yield and 16 percent on protein yield. Productive life receives more weight than any other trait at 22 percent. This is partly a function of high feed costs. In particular, growing or purchasing replacements is not cheap and more are needed when cows have short herd-lives. Bulls with higher productive life PTA (Predicted Transmitting Ability) also have more "trouble-free" daughters that have less disease.