Additive Genetic, Non-additive Genetic and Permanent Environmental Effects for Female Reproductive Performance in Seasonal Calving Dairy Cows

Abstract Text:  The objective of this study was to estimate additive genetic, non-additive genetic and permanent environmental components for a range of fertility traits in nulliparous and multiparous seasonal calving dairy cattle. Fertility information including calving dates, as well as information on services, pregnancy diagnoses, slaughter and animal movements (including death) was available for 373,877 cows. Variance components were estimated using (repeatability where appropriate) animal models. Heritability of the fertility traits varied from 0.001 to 0.04 while repeatability estimates varied from 0.05 to 0.11. Coupled with the significant heterosis effects of up to 12% of the phenotypic mean for some fertility traits, suggests that non-additive genetic and permanent environmental contribute substantially to differences among cows in reproductive performance.

Keywords:

fertility

genetics

permanent environment