The single factor test design method was used in this experiment to study the effect of chitosan oligosaccharide, a new green feed additive, on the production performance, egg quality, serum biochemical index, intestinal microbial population and interleukin-2(il-2) and tumor necrosis factor (tnf-ct) gene expression in the spleen.
In this study 512 58-week-old laying hens with similar weight and good, randomly divided into 4 treatment groups ,4 replicates per treatment group, and 32 chickens per repeat. The control group fed the standard basic diet, the experimental group fed the basic diet to add 300 mg/kg、600mg/kg、900mg/kg molecular weight lkda chitosan oligosaccharide feed, the test period was 42 d.. The total weekly intake, total egg weight, feed-egg ratio and egg laying rate of laying hens were measured at a fixed time every week. The serum biochemical indexes, the number of intestinal microbes, the index of living spleen and the expression of tof-a and il-2 immune genes in spleen were measured at the end of the experiment.
Conclusion: This experiment showed that adding chitosan oligosaccharides with different gradient molecular weight of lkda in laying hens diet showed that adding chitosan oligosology and reduce the number of Bifidobacterium and E. coli. promote the increase of tnf-a and il-2mrna expression in spleen, which can significantly improve the immunity of laying hens. The optimum dosage of low molecular weight chitosan oligosaccharide for laying hens feed was 300~600 mg/kg..