Immunopotentiators improve the antioxidant defense, apoptosis, and immune response in Shaoxing ducklings.

The abuse of antibiotics for agricultural purposes has been under scrutiny. Therefore, there is an urgent need to find antibiotic substitutes in animal production. The effects of chlorogenic acid, β-D-Glucan, astragalus flavone, CpG-DNA, and chicken IgG on spleen antioxidant capacity, apoptosis, and the immune response in Shaoxing ducklings were investigated in this study. The ducklings treated with β-D-Glucan, astragalus flavone, CpG-DNA, and chicken IgG showed significant reduction in catalase and superoxide dismutase activities. The five immunopotentiators facilitated caspase 3 expression and reduced Bcl2 expression in the spleen. Compared to the control group, the protein level of COX2 was significantly upregulated in the chlorogenic acid, CpG-DNA, and chicken IgG groups. The protein level of iNOS expression was significantly improved in all immunopotentiator groups, except for the astragalus flavone group. The five immunopotentiators induced IL-1β, IFN-α, IFN-β, TNF-α, RIG-I, TLR3, and TLR7 gene expression. In summary, chlorogenic acid, β-D-Glucan, astragalus flavone, CpG-DNA, and chicken IgG, as immunopotentiators, improved the innate immune response in the ducklings, which not only provides a new avenue for the development of efficient approaches to prevent pathogen infections, but also offers an alternative to antibiotics in animal production.