Preweaning gain rate of beef heifers and postpartum nutritional level, as cows, on milk production and composition and performance of their calves

The preweaning weight gain rate of beef heifers and its effects on their subsequent performance as cows, was studied. The weight gain rates evaluated as heifer calves before weaning were low (below 350 g/day) and moderate (above 350 g/day). As cows and after calving, they were kept together with their calves until weaning on native (NP) or cultivated pasture (CP). The cows while heifers were weighted at birth and at weaning with seven months. As cows they were weighted with their calves 24h after calving, at 14, 42, 70, 98, 126, 182 days postpartum, and at weaning when the calves reached average age of 228 days. The milk yield and the sampling for the evaluation of milk composition were taken at the same day of the weighing of the cows, with exception at birth. Weight rates below 350 g/day until seven months, did not affect the future weight of the heifers, due to compensatory gain after weaning. Heifers with weight gain rates below 350 g/day until seven month, as cows produced more milk (4.83 vs 3.71 L/day), total fat (47.4 vs 35.9 kg), lactose (52.6 vs 39.7 kg), total dry extract (140.4 vs 107.2 kg) and nonfat dry extract (94.8 vs 71.2 kg), calves with higher weight gain (717 vs 617 g/day) and heavier at weaning (189 vs 166.1 kg), than cows that showed as heifer-calves weight gain rates above 350 g/day.

total dry extract; weight gain; fat; lactose; cultivated pasture; native pasture


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