Effects of dietary superoxide dismutase on broiler growth performance, immune performance, antioxidant capacity and intestinal function

Abstract: [Objective] This experiment aimed to study the effects of superoxide dismutase (SOD) supplementation in diet on growth performance, immune performance, antioxidant capacity and intestinal function of broilers, and to provide a reference for the application of SOD in livestock and poultry. [Methods] 300 one-day-old male AA broilers were randomly divided into 5 groups, with 6 replicates in each group and 10 chickens in each replicate. Among them, the control group was fed a basic diet, while groups A, B, C and D were fed a basic diet supplemented with 100, 200, 400 and 800 mg/kg SOD, respectively. The experiment lasted for 42 days. The feed intake of the flock was recorded daily. After the experiment, one chicken was randomly selected from each replicate, given water and fasted for 12 h, and then weighed. Samples of immune organs, blood, liver and intestines were collected to determine the growth performance, immune performance, antioxidant capacity and intestinal function indicators of the broilers. [Results] Compared with the control group, (1) the feed conversion ratio of broilers aged 1 to 21 days in group B was significantly reduced (P<0.05). (2) The thymus index and bursa of Fabricius index of broilers in groups A to D showed an increasing trend, but the difference was not significant (P>0.05); the spleen index of broilers in groups B and C was significantly increased (P<0.05). (3) There was no significant change in the content of immunoglobulin A (IgA) in the serum of broilers in groups A to D (P>0.05); the content of IgG and IgM in the serum of broilers in group B was significantly increased (P<0.05). (4) The total antioxidant capacity (T-AOC), glutathione peroxidase (GSH-Px), and T-SOD activities in the serum of broilers in groups B and C, as well as the T-AOC and T-SOD activities in the liver, were significantly increased (P<0.05), while the MDA content in the serum and liver was significantly decreased (P<0.01); the GSH-Px and catalase (CAT) activities in the liver of broilers in group B were significantly increased (P<0.05); the MDA content in the serum of broilers in group D was significantly increased (P<0.05). (5) The length and weight of the duodenum and jejunum of broilers in group B were significantly increased (P<0.05). The trypsin activity in the duodenum and jejunum of broilers in groups B and C were significantly increased (P<0.05). [Conclusion] Under the conditions of this experiment, adding 200 mg/kg SOD to the diet can improve the antioxidant capacity, immunity, intestinal function and growth performance of broilers aged 1-21 days.