Effects Of Chitosan On Growth Performance, Immune Function, Blood Indexes And Intestinal System In Broilers

The present experiment was conducted to study the effects of dietary chitosan (0, 50, 200, 500, 1000 and 2000 mg/kg, respectively) on growth performance, immune functions, blood indexes, and intestinal system in broilers. In the experiment, single-factor test design was adopted, and a total of 240 1-day-old healthy male Arbor Acre broilers were selected and randomly allotted into six treatments, each treatment consisted of five replicates with eight broilers in each replicate. The feeding trial lasted 42 days, and experimental diets and water were available ad libitum during the entire experimental period. The experimental results were showed as follows:(1) The effects of chitosan on growth performance in broilers were related to the additive dose of chitosan in diets. The lower dose of chitosan had a better growth-promoting action, especially, the dose of 200 mg/kg had the best effect.(2) The dietary chitosan increased the Newcastle disease antibody titers and the peripheral blood T lymphocyte clusters of differentiation (CD3+, CD4+ and CD8+), and raised the blood single-core-macrophages phagocytic index and serum immunoglobulin in broilers. To the Newcastle disease antibody and the single-core-macrophages phagocytic index, the dose of 50~200 mg/kg chitosan performed better effects. However, to the peripheral blood T-lymphocyte clusters of differentiation (CD3+, CD4+ and CD8+) and serum immunoglobulin, the dose of 500~1000 mg/kg chitosan performed better effects.(3) Dietary chitosan reduced serum cholesterol and triglycerides in broilers, and the dose of 200 mg/kg chitosan showed the best effect. In addition to that, dietary chitosan could increase the concentrations of growth hormone (GH) and insulin-like growth factor (IGF-I), and reduce the levels of corticosterone (Cort) in serum of broilers, and the dose of 200 mg/kg chitosan showed the best effect.(4) The dose of 500~1000 mg/kg chitosan reduced the population of E. coli in ileum and cecum, but increased the population of Lactobacillus and Bifidobacterium, and improved the content of volatile fatty acid in cecum. In addition, the dose of 50~2000 mg/kg chitosan increased gut villus height and recess depth, and reduced the width of gut villus in broilers.