Background: An immune system is a system of biological structures and processes within an organism that protects against diseases by identifying and killing pathogens and tumor cells. Development of novel natural immune enhancers is an urgent issue.
Methods: In experiment 1, Newcastle disease antibody titer, levels of IL-6, IL-10 and IFN-γ, and changes in CD3(+), CD4(+) and CD8(+) cells were analyzed. In experiment 2, diarrhea, respiratory symptoms and mortality of broilers were measured.
Results: In experiment 1, the results showed that the immune response, such as Newcastle disease antibody and CD4(+) T cells, would be significantly activated by feeding with chitosan and its derivative during 27 days. In experiment 2, the results demonstrated that diarrhea, respiratory symptoms and the mortality of the commercial medicine treatment group were decreased, with infection days increased. However, the mortality of broilers was significantly decreased, while feed intake and weight gain of the birds were significantly increased in the group treated with chitosan and its derivative as compared with other groups.
Conclusion: Chitosan and its derivative have strong potential in immune enhancement and disease control, and can be used as a feed additive.