Is high protein diet a good nutrition strategy for broiler chickens reared at heat stress condition?

摘要

It is well lcnown that heat stress, in growing broiler chicks, impair the performance. Ain Baziz et al. (1996) reported that 53% of the impairment in the performance was due to reduction in feed consumption, but the last 47% was due to the direct effect of ambient temperature, per se. One of the approaches that have been proposed to avoid the effect of heat stress in broilers is related to the protein content in the diet, since protein metabolism is deeply involved in the caloric increment, as compared with fat or carbohydrate. According to Gonzalez-Esquerra and Leeson (2006) the Arg:Lys ratio, Met source and time to exposure to heat stress affect protein utilization in hyperthermic birds. Thus, this study was conducted aiming to verify if the increase of protein content in the diet, maintaining the Arg:Lys ratio, affects broiler chicks performance when reared at different envifonmental conditions.