Effects Of Dietary Chitosan Oligosaccharides Supplementation On Immune-related Hematological Parameters In Broilers

Chitosan oligosaccharides(COS)is a type of oligosaccharides,which is obtained by chemical and enzymatic hydrolysis of chitosan.COS has a higher activity and better physiological functions than chitosan,because of a low molecular weight,good solubility,low viscosity,and easily absorbability of the body.COS have several biological functions,including anti-bacterial,anti-tumor,anti-oxidant,anti-inflammatory and immunological enhancement functions.COS has been widely exploited for biomedical and pharmaceutical applications.The objective of this study was to investigate the effect of COS diets on the percentages of peripheral blood T-cell subsets,serum immunoglobulins contents,serum cytokines contents and oxidative stress parameters in broiler chickens by feeding on a corn-soybean basal diet and COS supplemented diets containing different concentration of COS.A total of 160 1-day-old healthy Arbor Acres male broiler chicks were randomly allotted to four dietary treatments with eight replicates in each treatment,and with five chickens in each replicate.The basal diet was mainly composed of corn and soybean.The broiler chickens in the four treatments were fed on diets as follows:control group(basal diet),COS Ⅰ group(200 mg/kg COS),COS Ⅱ group(350 mg/kg COS),and COS Ⅲgroup(500 mg/kg COS).Broilers were provided feed and water ad libitum for 42 days.Blood was collected at 21 and 42 days of age.The results were as follows:1.Effects of COS supplementation on the percentages of peripheral blood T-cell subsets in broilers showed that dietary COS could significantly improve the percentages of peripheral blood T-cell subsets in AA broilers at 21 and 42 days of age(P<0.05),which was showed as the percentages of CD3+,CD3+CD4+ and CD3+CD8+ T cells in the dietary COS supplemented groups were increased(P<0.05,P<0.01)than those in the control group.2.Effects of COS supplementation on serum immunoglobulins in broilers showed that that dietary COS could significantly improve the concentrations of IgG,IgM and IgA in AA broilers at 21 days of age(P<0.05),and the concentrations of IgG and IgA were notly higher(P<0.05)in the COS groups than those in the control group at 42 days of age,although there was no significant difference between the experimental groups for the concentrations of IgM.3.Measurement of the effects of dietary COS on serum cytokines in broiler chickens showed that the concentrations of cytokines,including IL-1β,IL-2,IFN-γ and TNF-α,were markedly increased in the COS groups at 21 and 42 days of age(P<0.05)when compared with those of the control group,and the supplementation of 350 mg/kg COS in the diet showed the maximum value of serum cytokines concentrations.4.Diets supplemented with 200,350 and 500mg/kg COS could significantly enhance the activities of T-SOD,GSH-Px,CAT and GR(P<0.01),reduce the content of MDA(P<0.05),increase the content of GSH(P<0.05)and improve T-AOC and the capacity of inhibiting hydroxyl free radical(P<0.05).Especially,chickens fed on dietary 350mg/kg COS showed the optimal antioxidative capacity.