Introduction: Heat stress has become a significant concern for the global poultry industry as a result of climate change. This condition can adversely affect growth, gut health, immune function, production levels, and reproductive performance, and can lead to lipid peroxidation in poultry. Therefore, this study aimed to evaluate Interleukin 6 and 10 immune responses, anti-oxidant indices, serum biochemistry, and hepatic and splenic histopathology of heat-stressed broiler chickens supplemented with α-lipoic acid (α-LA) in their diet.
Materials and methods: A total of two hundred and four unsexed day-old Arbor acre broiler chicks were randomly divided into four treatment groups and replicated three times to receive α-LA at 0, 50, 100, and 200 mg/kg, respectively in a completely randomized design for 42 days after a one-week adjustment period. The average temperature in the morning and afternoon was 27.9℃ and 35.1℃, respectively, while the morning and afternoon humidity was 73.1% and 44.1% respectively. Feed and water were provided ad libitum. At the end of the feeding trial, samples were taken for cytokines (interleukin-6 and 10), anti-oxidant, serum biochemistry, and hepatic and splenic histopathology analyses.
Results: An inverse relationship was observed between pro-inflammatory (IL-6) and anti-inflammatory (IL-10) cytokines whereby, IL-6 levels decreased while IL-10 levels increased relative to increasing α-LA levels in treatment groups. The treatment groups also indicated an increasing trend with rising levels of α-LA for superoxide dismutase, catalase, glutathione, and total antioxidant capacity. The α-LA significantly influenced malondialdehyde production, showing its reduction with rising levels of α-LA. A decrease in serum glucose and low-density lipoproteins was observed with increasing levels of α-LA, while high-density lipoproteins increased with increasing levels of α-LA. Cholesterol, triglycerides, very low-density lipoproteins, aspartate transaminase, alanine transaminase, and alkaline phosphate remained unchanged across the treatment groups.
Conclusion: α-LA supplementation at 200mg/kg in diet had the highest effects on immune responses of interleukin 6 and 10, antioxidant, serum biochemical indices, and histopathology of heat-stressed broiler chickens.