The Effects of Vitamin E and Selenium on the Immune and Antioxidant Functions of Gushi Broiler Chickens After Immune Stress

This study investigated the effects of dietary supplementation with Vitamin E (<b>VE</b>) and selenium (<b>Se</b>) on immunostressed broilers. In the experiment, a total of 576 Gushi chickens were randomly allocated into 12 groups. They were respectively fed diets with different levels of VE and Se. Lipopolysaccharide (<b>LPS</b>) immune treatment was administered at 23, 25, and 27 days of age. At 28 days of age, the antioxidant indicators and immune factors in their serum, liver, and intestine were measured. The results indicated that (1) LPS treatment significantly elevated the contents of nitric oxide (<b>NO</b>) and nitric oxide synthase (<b>NOS</b>) in the duodenum and jejunum (<i>p</i> < 0.01). Conversely, adding VE and Se to the diet of LPS-treated chicks could significantly decrease the content of NO in the duodenum and the activities of NOS in the duodenum and jejunum (<i>p</i> < 0.01). (2) LPS treatment significantly decreased the content of malondialdehyde (<b>MDA</b>) in the liver of broilers, glutathione peroxidase (<b>GSH-P</b>x), and the activities of serum superoxide dismutase (<b>SOD</b>) (<i>p</i> < 0.01). Dietary supplementation of selenium could significantly reduce the content of MDA (<i>p</i> < 0.01), and the treatment groups with 200 mg/kg VE and 0.6 mg/kg Se exhibited the most favorable effects. (3) Adding Se or VE to the diet of LPS-treated chicks could significantly increase the thymus index and spleen index (<i>p</i> < 0.05) and significantly decrease the bursa of Fabricius index (<i>p</i> < 0.05). Among them, the thymus index was the highest in the 100 mg/kg VE group, and the interaction of the three factors had a significant influence on the thymus index and bursa of Fabricius index (<i>p</i> < 0.05). (4) The level ofinterleukin-6 (<b>IL-6</b>) in the serum of broilers in the LPS treatment group was significantly increased. However, selenium and Vitamin E were added to the diet of LPS-treated chicks to reduce the contents of serum IL-6 and IL-8, as well as adrenocorticotropic hormone (<b>ACTH</b>) and tumor necrosis factor-α (<b>TNF-α</b>). Moreover, the interaction of the three factors has a significant impact on immune indicators (<i>p</i> < 0.01). In conclusion, adding 100–200 mg/kg of VE and 0.6 mg/kg of Se to the diet of broiler chickens has certain advantages in enhancing immunity and antioxidant capacity.