Abstract:

In order to explore the effects of chitosan on intestinal barrier of weanling pigs, thirty piglets with an average body weight of (6.62±0.59) kg were challenged with enterotoxigenic Escherichia coli (10⁹ cell per head) during preliminary trial period and randomly assigned to three treatment groups, a basal diet was added in control group, 50 mg·kg^-1 chlortetracycline, 300 mg·kg^-1 chitosan were added in the experimental groups, respectively, for 21 d. The results showed that, compared with the control group, chitosan could decrease the level of D-Lactate(P＜0.05) and the activity of DAO(P＜0.05) in plasma and the level of ET-1(P＜0.05) in serum, but it had no significant effect on the contents of NO(P＞0.05) in serum. The result of immunohistochemistry showed that the protein expression levels of Occludin (P＜0.01) and ZO-1 (P＜0.05) in piglets jejunum mucous added with chitosan were increased. The result of fluorescence quantitative PCR showed that the expression abundances of Occludin (P＜0.01) and ZO-1 (P＜0.05) mRNA in piglets jejunum mucous added with chitosan were improved. These result indicate that diet supplemented with 300 mg·kg^-1 chitosan can protect greatly the intestinal barrier of early weanling piglets from injuring.