Effects Of Different Molecular Weight Chito-oligosaccharides On Growth Performance And Immune Function Of Laying Hens

This study was conducted to evaluate the effects of dietary supplementation withdifferent molecular weight chit-oligosaccharide (COS) on egg production, egg quality, bloodprofiles, intestinal morphology, IL-2and TNF-α gene expression in laying hens. A total of480seventy-weeks old laying hens were randomly allocated to4treatments with4replicatepens per treatment and30birds per pen. The control group was fed basal diet, the test groupwere fed200mg/kg COS whose molecular weight was1kDa,3kDa,8kDa respectively basedon the basal diet, The experiment lasted for42days. ADFI, Average egg weight, Laying rateand Feed/egg ratio were calculated each week. Egg Qualities was determined on21d. bloodprofiles, intestinal morphology, Spleen index, IL-2and TNF-α gene expression weredetermined on42d. Results:Dietary supplementation of COS was no significant differently in ADFI, Average eggweight, Laying rate and Feed/egg ratio (P>0.05).There was no significant differently in Yolk/egg and Eggshell/egg ratio (P>0.05).Dietary supplementation of COS increased Albumen height (P>0.05). Compared with thecontrol treatment, dietary supplementation of1kDa,3kDa,8kDa COS Respectively improved3.70%,5.20%,12.71%on Haugh-units (P<0.05). Egg shap index was significant lower thancontrol treatment in3kDa COS treatment (P<0.05). Dietary supplementation of1kDa,3kDaCOS were inceased Eggshell strength (P>0.05).Dietary supplementation of COS was no significant differently in TP, ALP, CHOI, GOT,GPT, Ca and P in serum (P>0.05). The level of Glu in Serum was decreased5.86%in3kDaCOS treatment (P<0.05). The level of Triglycerides was respectively decreased39.9%and23.2%(P<0.05).There was no significant differently in Spleen index. Dietary supplementation of1kDaCOS has decreased the number of E. coli, and bifidobacteria.The level of the TNF-α Gene Expression in spleen was significantly higher in3kDatreatment (P<0.05). Dietary Supplementation of1kDa,3kDa COS treatment improved IL-2 gene expression, and the highest level appeared in1kDa treatment.In conclusion, dietary supplementation of200mg/kg different molecular weight COSappeared to improve egg haugh units,3kDa treatment can decreased the level of Triglyceridesand GLU in Serum, dietary supplementation of1kDa treatment can decrease the number of E.coli, and Bifidobacteria in appendix,1kDa treatment can improved the IL-2Gene Expression,3kDa treatment can improved TNF-α Gene Expression in spleen.