Dietary Selenium Sources in Combination with Alpha-lipoic Acid in Broiler Chickens: Influence on Growth Performance, Serum Antioxidant Activity, Meat Quality, Immune Status and Ileal Nutrient Digestibility.

This study evaluated the interactive effects of different dietary selenium (Se) sources and alpha-lipoic acid (ALA) supplementation on growth performance, serum antioxidant status, meat quality, immune responses, and ileal nutrient digestibility in broiler chickens. A total of 450 male Ross 308 chicks were randomly assigned to six dietary treatments in a 2 × 3 factorial design, comprising two levels of ALA (0 or 300 mg/kg) and three Se sources including inorganic sodium selenite (SS), organic selenomethionine (SM), and nano-selenium (NS) at 0.3 mg/kg. Each treatment included five replicates of 15 birds. Results demonstrated that both Se source and ALA significantly improved body weight gain and feed conversion ratio (P < 0.05), with the greatest performance observed in birds fed diets with SM or NS sources and ALA supplement. Serum antioxidant activity was enhanced by SM and NS, as evidenced by increased glutathione peroxidase activity and reduced malondialdehyde (MDA) levels (P < 0.05). ALA supplementation further reduced serum MDA concentrations. Meat oxidative stability and water-holding capacity (WHC) were significantly improved in birds receiving NS and ALA supplemented diets, with interaction effects observed (P < 0.05). In immune response, IgG levels were elevated in the birds fed diet supplemented with SM or NS, while ALA independently improved IgG and bursa weight (P < 0.05). Serum Se concentrations reflected dietary Se source, with interaction effects noted. However, no significant effects were detected for nutrient digestibility in response to the dietary treatments. In conclusion, dietary inclusion of ALA in combination with SM or NS can synergistically enhance antioxidant capacity, immunity, and meat quality, thereby supporting improved growth performance in broiler chickens.