CALVING AND PREWEANING PERFORMANCE OF CROSSBRED PROGENY OF SOME FOREIGN AND DOMESTIC BEEF CATTLE BREEDS

Abstract

Charolais-, Simmental- and Limousin-sired calves are compared for calving traits and preweaning growth based on observations of 3939 calves born in 48 western Canadian beef cow herds of Hereford, Angus and Shorthorn breeding during the period 1970–1972. Hereford cows produced calves with longer gestation lengths, higher birth weights, slower preweaning growth, and lower weaning weights than Angus cows. Shorthorn cows produced progeny with the shortest gestation lengths and intermediate performance in other traits. Limousin sires produced calves with the longest gestation lengths, the least calving difficulty, the lightest birth weights, the lowest birth-to-weaning mortality, and the slowest preweaning growth. Charolais-sired and Simmental-sired calves did not differ significantly in gestation length, postnatal mortality or preweaning growth rate, but Simmental-sired calves were lighter at birth and calved more easily. Breed-of-sire effects interacted with breed-of-dam effects for birth weight and with sex-of-calf effects for calving ease and most measurement traits, but these interactions did not generally involve a re-ranking of sire breeds. The economic impact of the results is briefly discussed. Key words: Beef cattle, breed effects, preweaning traits