Productivity and efficiency of cow herds submitted to two weaning ages

It was aimed in this work to evaluate the productivity and efficiency of beef cows submitted to weaning of their calves at 76 days (early weaning) or at 148 days (weaning at conventional age) after calving during three consecutive years. It was evaluated pregnancy rate, birth and weaning, gain weight of the calves and cows at conventional weaning, weight at conventional weaning of calves and cows, production of weaned calves per cow and calf production index. Pregnancy rate in the herd submitted to early weaning (86.34%) was higher than in the conventional weaning (55.5%). Early weaning cows showed higher birth and weaning rates when compared to conventional weaning (83.6 and 83.6% vs. 47.5 and 44.5%, respectively) besides a higher production of calves (183 vs. 114). Early weaning cows produced 60.5% more calves than the conventional weaning cows. Conventional weaning calves gained more weight from birth to weaning (97.9 vs. 83.4 kg, respectively). Early weaning cows had more weight gain from calving to weaning (42.5 vs. 18.7 kg, respectively), and regarded to calf production index, they were more efficient (efficiency of the herds). At the average of the three years, the early weaning of the calves allows higher calving rates and weaning to the cows, in addition to a higher index of calf kilogram index produced in relation to weaning at conventional age. A produtividade e a eficiência de vacas de corte submetidas ao desmame de seus bezerros aos 76 dias (desmame precoce) ou aos 148 dias (desmame à idade convencional) pós-parto foram medidas durante três anos consecutivos. Avaliaram-se as taxas de prenhez, natalidade e desmama, o ganho de peso de bezerros e de vacas do parto ao desmame convencional, o peso à desmama convencional de bezerros e vacas, a produção de bezerros desmamados por vaca e o índice de produção de bezerros. A taxa de prenhez no rebanho submetido ao desmame precoce (86,4%) foi superior à do desmame convencional (55,5%). Vacas do desmame precoce tiveram maiores taxas natalidade e de desmame em comparação às do desmame convencional (83,6 e 83,6% vs 47,5 e 44,5%, respectivamente), além de maior produção de bezerros (183 vs. 114). As vacas do desmame precoce produziram 60,5% a mais de bezerros que as vacas do desmame convencional. Os bezerros de desmame convencional foram os que ganharam mais peso desde o nascimento até o desmame (97,9 vs 83,4 kg, respectivamente). As vacas do desmame precoce tiveram maior ganho de peso do parto até o desmame