Effects of cold stress on physiologic metabolism in the initial phase and performance of broiler rearing

This study aimed to investigate the effects of 8 h of cold stress (18 °C) every day in broiler chicks during the first 7 days of rearing on crop filling analysis, yolk sac consumption, digestive and immune organs weights, and physiological metabolism at seven days and performance between 1 and 35 days. Cobb500 male broiler chickens (n = 274) were randomly assigned to two treatments. The treatments consisted of varying environmental temperatures during the first week post-housing. Chicks were reared at a thermoneutral temperature (32 °C) or under cold stress (18 °C) for 8 h/day during the first week, and both groups were subsequently reared at a thermoneutral temperature for 8–35 days. The thermoneutral group reached 90% full crop after 48 h of housing (P 0.05, while the cold-stressed group had elevated heterophil/lymphocyte count at day 7 (P