Characterization of heat stress affecting the growth performance, blood biochemical profile, and redox status in male and female broilers at market age.

Abstract

This study investigated the effects of acute heat stress (HS), sex, and their interaction on growth performance, serum biochemical and redox status in the later stage broilers. Two hundred 38-day-old Ross 308 chicks were allocated in a factorial arrangement of 2 × 2 (temperatures and sexes) with 5 replicates of 10 bird each. Thermoneutral and heat-stressed broilers were raised at 24 ± 1°C or 32 ± 1°C from day 38 to 39, respectively. HS decreased the average daily feed intake (ADFI) and average daily gain (ADG) whereas it increased feed conversion ratio (FCR), rectal temperature (RT), and respiratory rate (RR) in broilers exposed to high temperature for 24h and 48h. Moreover, RT, RR, serum glucose, and HDL-C levels increased while triglyceride (TG), total superoxide dismutase (T-SOD), and glutathione peroxidase (GPx) decreased in broilers exposed to high temperature for 12h. Male broilers had higher final body weight (FBW), ADFI, ADG, total protein carbonyl group, and lower FCR and T-SOD than females in HS condition for 24h and 48h. Lower RT, serum albumin, HDL-C, activities of T-SOD and GPx were observed when compared with those of males in HS condition for 12h. There were significant temperature × sex interactive effects on ADFI, ADG, and TG in broilers exposed to high temperature for 24h and 48h. The present study suggests that the acute HS negatively affects growth performance which is accompanied by the disorder of serum nutritional metabolism and imbalance of redox status in later stage broilers. Some parameters presented sexual differences that suggested it may be more effective to alleviate the negative effects of HS when broiler producers take into account the gender of broiler.