Selenium-enriched Bacillus subtilis Improves Growth Performance, Antioxidant Capacity, Immune Status and Gut Health of Broiler Chickens

This study aimed to investigate the effects of selenium (Se) - enriched Bacillus subtilis (Se-BS) on growth performance, antioxidant capacity, immune status and gut health in broilers. A total of 240 day-old Arbor Acres broilers were randomly allotted to four treatments of a basal diet supplemented with no Se, sodium selenite (SS), B. subtilis (BS), and Se-BS and raised for 42 days. The results showed that Se-BS supplementation significantly increased body weight (BW), average daily gain, the activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and peroxidase (POD), total antioxidant capacity (T-AOC), interleukin (IL) -2, IL-4 and immunoglobulin (Ig) G contents in plasma, the index and wall thickness of duodenum, the villus height and crypt depth of jejunum, GPx-1 and thioredoxin reductase 1 (TR-1) mRNA levels in liver and intestine ( P  < 0.05), and decreased feed conversion ratio (FCR) and malondialdehyde (MDA) content in plasma ( P  < 0.05). Compared with the SS and BS groups, Se-BS supplementation significantly increased BW, the activities of GPx, CAT and POD, and the contents of IL-2, IL-4 and IgG in plasma, the index and wall thickness of duodenum, crypt depth and sIgA content of jejunum, and GPx-1 mRNA level in liver and intestine ( P  < 0.05), and decreased FCR and MDA content in plasma ( P  < 0.05). This study provides scientifc basis for further understanding Se-BS as a more effective measure to improve growth performance and healthy of broilers.