Sire x herd-interaction for milk performance traits and for culling by first-calf cows

摘要

The paper has the aim of proving the existence of genotype x environmental interactions at a current data material. The interaction sire x herd is of special interest. Since the single bull has always to be evaluated in the practical breeding work/selection or in the routine estimation of breeding values, a model was consciously chosen to have included exactly this type of interaction. Interactions were found out for different culling rate (= categorical data) on the basis of the logistical regression for the first time.A significant sire x herd interaction can be shown for most of the examined traits in dairy cattle.