Desenvolvimento de bezerros de corte desmamados aos 80 ou 152 dias até os 15-16 meses de idade

Abstract

The performance of beef calves submitted to two weaning ages (early weaning, at an average age of 80 days; conventional weaning, at an average age of 152 days) was evaluated. One hundred and five Braford calves born in 2004 and 2005, after weaning, were kept on pastures cultivated with pearl millet (Pennisetum americanum) in the first and second summer and, in winter/spring, they were kept on pastures with oat and ryegrass (Avena strigosa Schreb + Lolium multiflorum Lam). Body weight (BW), average daily weight gain (ADWG) and body condition (BC) were evaluated. There was a significant interaction among age at weaning and year for daily weight gain for early weaning as well as for conventional weaning on oat and ryegrass pastures. In the period between the two weaning ages, the daily weight gain in early weaning was higher in 2004 than in 2005 (0.499 vs 0.468 kg, respectively) and for early weaning, higher daily weight gain occurred in 2005 (0.493 vs. 0.631 kg, respectively). On oat and ryegrass pasture, average daily weight gain for early weaned animals in 2004 (0.666 kg) was lower than in 2005 (0.760 kg), however, there was no difference among years for conventional weaned animals (0.720 and 0.723 kg, respectively). During second summer periods, average daily weight gain did not differ among early and conventional weaned animals. Weight of early weaned animals (158.2 kg) was higher than conventional weaned animals (147.7 kg) in the beginning of winter grazing; however, it did not differ at the end. In the end of the summer, when calves were 15-16 months of age, body weight was similar among early weaned (340.1 and 4.14 points) and conventional (332.8 kg and 4.15 points) weaned animals. Final body condition, in 2004, was higher (4.34) than in 2005 (3.96 points). Calves weaned at 80 days of age and adequately fed present similar development as those weaned at 152 days of age, achieving development and finishing conditions to be slaughtered for specific markets at 15-16 months of age. © 2011 Sociedade Brasileira de Zootecnia.