Nutritional and managerial interventions on growth performance, nutrient transport-related genes and behavioral...

The present study aimed to investigate the effect of nutritional additives and management on performance, behavioral responses, energy metabolism and expression of stress, antioxidant, growth, and nutrient transport-related genes in broiler chickens under heat stress (HS). Experimental treatments including: 1) control group, 2) heat-stressed group (HS), 3) HS + vitamin E and organic selenium, 4) HS + vitamin C and coenzyme Q10, 5) HS + eubiotic, 6) HS + 10 % increase in methionine, 7) HS + 20 % increase in methionine, and 8) HS + ice and non-alcoholic beer. HS was applied from day 28 to 42 of age at 32 ± 1 °C, daily from 10:00 AM to 6:00 PM. The results showed that HS treatment significantly reduced feed intake and body weight gain compared with the control group, whereas supplementation with vitamin E + selenium and vitamin C + coenzyme Q10 fully alleviated these negative effects, restoring performance to levels comparable to the control. HS increased scores for pecking, panting, resting, and wing spreading, while the ice and beer treatment completely mitigated these behavioral stress responses. HS suppressed hepatic expression of HSP70, antioxidant genes, IGF1 and SLC3A1. Overall, these findings highlight that targeted nutritional supplementation combined with management strategies can effectively mitigate HS-induced impairments in broiler chickens, improving performance, behavioral responses, energy metabolism, and gene expression.