Heterosis in Reproductive Performance of Beef Cows

Abstract

Five years of reproductive data on four straightbred and 12 types of crossbred cows of Angus, Brahman, Brangus and Hereford breeding were examined to determine the degree of heterosis exhibited in calf-crop percent. Crossbred cows excelled straightbred cows by 9.6% on calf-crop percent (P<.01). No significant differences in preweaning death losses were found. Reciprocal crossbred cows were compared individually and collectively with the two parental breeds to evaluate heterosis. No significant difference was found between reciprocal crossbred cows. Only those crossbred cows with the Brahman breed as one of the parental breeds exhibited significant differences in reproductive performance over their combined parental straightbred performance. Calving percent for all groups of reciprocal crossbred cows was higher than their respective parental average.