The effects of spring versus summer calving on beef cattle reproductive and growth performance in western Canada

EC (93.0%) vs. LC (95.8%); calving rate (P� 0.89) EC (92.0%) vs. LC (91.7%) or proportion of calves born alive (P� 0.85) EC (99.5%) vs. LC (99.6%). The average length of calving season was not different (P� 0.26) between the two systems. The EC cows had greater (P � 0.002) BW losses from calving to breeding but greater (P� 0.001) BW gain from breeding to weaning than LC cows. Although calves born in LC had greater birth BW (P� 0.003) than EC calves, calf weaning rate (P� 0.01) and calf weaning BW (P B0.0001) were greater in EC. The higher weaning rate and higher weaning BW with EC has the potential to increase cow-calf productivity and may be more attractive to beef producers in western Canada.