The study was conducted to evaluate productive and reproductive performance of 52 crossbred Charolais × Nellore beef cows on natural pasture. The experiment started on August 04, 2003, when pregnant cows were uniformly distributed by weight and body condition at two stocking rates (CA280 = 280 kg LW/ha and CA360 = 360 kg LW/ha). Early weaning was imposed to 26 cows when calves reached average of 100 days of age and conventional weaning, when calves were approximately 180 days old. Cows submitted to early weaning had average daily gain higher than cows submitted to conventional weaning (0.539 vs. 0.257 kg/day, respectively). There was significant interaction between weaning ages and periods for body condition of cows. Cows submitted to early weaning presented higher body condition at conventional weaning (3.5 vs. 2.8) and at the end of mating period (3.0 vs. 2.8) than the conventional weaning. The stocking rate did not significantly affect the average daily gain and body condition of cows (CA280 = 0.101 kg/day, 2.7 and CA360 = 0.214 kg/day, 2.7, respectively). The pregnancy rate of cows under early weaning (60.0%) was significantly better than for those under conventional weaning (12.0%); however, the stocking rates did not differ (CA280 = 7.7% vs. CA360 = 15.4%). In calves submitted to early weaning, average daily gain and live weight at 180 days were significantly lower than those of calves at conventional weaning. The post-partum management of cows and two ages of weaning calves evaluated did not affect the development of calves until 14 months of age.
average daily gain; body condition; body weight; pregnancy rate; weaning ages
