Productive Performance of Pre-Weaned Calves Reared in the Pantanal

Abstract

Early weaning (EW) has been adopted in cattle breeding farms in Pantanal as a strategy to increase the rate of pregnancy in cows. The primary income of these properties is the production of beef calves, and the price of these animals depends on their weight. Therefore, the calves subjected to EW should present weight similar to or higher than those of calves subjected to conventional weaning (CW). This study aimed to evaluate the productive performance of pure (Nellore) calves and crossbred (Nellore/Angus) calves reared in the Pantanal and subjected to either EW or CW. After EW, the calves were supplemented with concentrate at 1 kg/animal/day (low-energy diet) or 1% of live weight (high-energy diet). The weights adjusted to 300 days of age were higher for EW calves fed the high-energy diet (p<0.01) in both genetic groups. No significant differences were observed in the weight of EW animals fed the low-energy diet and CW animals (p>0.01), and animal weight was 241.17 and 236.27 kg in crossbred calves and 184.44 and 189.78 in Nellore calves, respectively. The EW adopted in this experimental model did not affect the productive performance of calves raised in the Pantanal.

Effects of Early Weaning on Performance and Carcass Quality of Nellore Young Bulls

“…Early weaning emerges as a promising strategy to optimize the metabolic status of cows, playing a crucial role in improving conception rates during the subsequent reproductive season [ 21 , 22 ]. A parallel study conducted by our research group involving 208 lactating cows (including those from the present study) revealed that cows subjected to early weaning showed an approximately 28% greater pregnancy rate in two fixed-time artificial inseminations [ 5 ].…”

“…Although early weaning is an interesting strategy to enhance the reproductive performance of cows, this practice can entail significant disadvantages for calves, mainly when adequate nutritional conditions are not provided after this period [ 25 ]. Studies on early weaning in beef calves have revealed that the implementation of post-weaning supplementation strategies can equalize the performance of traditionally weaned calves, especially when the latter do not receive supplementation [ 16 , 21 , 27 ]. In the present study, the results indicate that calves in the EW group exhibited reduced body weight compared with those in the CW group from 240 days of age and continuing throughout the experiment.…”