Effects of Crossbreeding on Reproductive Performance of Dairy Cattle

Abstract

Data for this study were taken on the reproductive performance of 86 first-generation female progeny in the Dairy Cattle Crossbreeding Project of the Illinois Agricultural Experiment Station. The seven measures used were services per conception, age at first calving, interval from first service to conception, gestation length, calving interval, calving date to first heat, and calving date to first service. For the seven measures used, estimates of the effect of system of mating were consistent, small, and nonsignificant. This evidence supports the concept of the relative unimportance of nonadditive gene action in effecting variation in the measures of reproductive performance used in this study. © 1961, American Dairy Science Association. All rights reserved.