Results from Crossing Beef × Beef and Beef × Dairy Breeds: Calf Performance to Weaning

Abstract

Data collected at the U. S. Range Livestock Experiment Station, Miles City, Montana, on 244 male calves and 254 heifer calves were used to estimate the amount of heterosis resulting from crossing beef cattle breeds. Cattle of the Hereford, Angus and Charolais breeds were mated to produce straightbred calves of each breed and all possible two-breed combinations in each of the years 1962 through 1965. In conjunction with the main study, 54 male calves and 34 heifer calves were used to compare Brown Swiss dams with dams of the three beef breeds as producers of crossbred calves. To produce beef X Brown Swiss calves, the Hereford, Angus and Charolais sires used in the main study were also mated, in each breeding season, with Brown Swiss females. Steer calves exhibited more heterosis for each of the observed traits than did heifer calves. For each trait, the over-all advantage of crossbreds over mid-parent average was significant for steer calves and nonsignificant for heifer calves. Heterosis for birthweight, preweaning daily gain, weaning weight and weaning score amounted to 4.4, 3.7, 3.8 and 2.2% for steer calves and 1.4, 2.0, 1.9 and 0.4% for heifer calves, respectively. The heaviest weights and greatest daily gains were exhibited by the progeny of the Brown Swiss dams. The average advantage shown by Brown Swiss dams over dams of the three beef breeds for steer and heifer calves, respectively, was 5.4 and 6.7 kg. for birthweight, 0.138 and 0.126 kg. for preweaning daily gain and 33.6 and 32.5 kg. for weaning weight. Conversely, dams of the beef breeds showed an average advantage of 2.3 and 1.5 units in weaning score of steer and heifer calves, respectively, over Brown Swiss dams. Average scores of all breed groups were, however, within the middle to high choice feeder grade.