Calving month and calf sex on the production and efficiency of herds

Abstract

Abstract The calving period influences productivity and reproductive efficiency the herds. The objective of this study was to evaluate two calving months (October and November) and their effect on the efficiency of a breeding herd for three consecutive years. A total of 298 Braford cows were evaluated at three, four, and five years of age, with their calves early-weaned at 148 days of age. The performance characteristics of the cow/calf pairs were evaluated with the calving month and calf sex as the independent variables. The animals were kept as a single group for the three years of observation. Cows calving in November were heavier and had a higher body condition score at calving. Cows calving in October were heavier and produced heavier calves at weaning. Male calves were heavier at birth and weaning than females (30.8 vs 28.6 kg and 118.9 vs 114.7 kg, respectively). The pregnancy rate was 82.35 and 69.23% for cows calving in October and November, respectively. Calving intervals were shorter in cows calving in November. Cows calving in October were more efficient compared with those calving in November, with a higher actual fertility rate. The production of kilograms of the calf/cow pair was higher for cows calving in October.