Feedlot Performance of Young Males Weaned at 72 or 210 Days

[摘要] - The experiment was conducted to evaluate the feedlot performance, from 210 to 408 days of age of calves weaned at 72 (T72) or 210 (T210) days. Thirty-six non castrated Braford (5/8 Hereford 3/8 Nellore) calves were used. The average weight at the beginning of the experiment was 209 (T72) and 192 kg (T210). The whole feedlot period was 168 days, divided in four periods of 42 days. The roughage:concentrate ratio was 60:40 for the first and second periods, 50:50 for the third period and 45:55 for the fourth period. No significant interaction was observed between weaning age and feedlot evaluation period for average daily dry matter intake (DMI) and average daily digestible energy intake (DEI), expressed per animal (DMID and DEID), per 100 kg of live weight (DMIP and DEIP) and per unit of metabolic weight (DMIM and DEIM), for average daily weight gain (ADG), feed efficiency (FE) and energy efficiency (EE). Animals weaned at 210 days presented higher DMIP (2.25 versus 2.07% of LW) and DEIP (7.05 versus 6.48% of LW) than animals weaned at 72 days. No difference was observed for DMID (6.75 versus 6.98 kg/day), ADG (1.066 versus 1.074 kg/day), FE (6.42 versus 6.72 kg of DM/kg of LW) and EE (20.18 versus 21.13 Mcal/kg of LW) for animals weaned at 72 or 210 days. Slaughter and hot carcass weight were similar, being, respectively, 424 and 232 kg for T72, 406 and 221 kg for T210 animals. The results showed that animals weaned at 72 days present feedlot performance, slaughter and carcass weight similar to those weaned at 210 days.

[学科分类] 兽医学

[关键词] Braford;early weaning;feedlot performance;normal weaning    Introdução A baixa rentabilidade apresentada pela pecuária de corte de ciclo completo atualmente tem forçado o pecuarista a buscar a melhoria dos índices reprodutivos do rebanho