Effects of low-molecular-weight chitosan on the growth performance, intestinal morphology, barrier function, cytokine expression and antioxidant system of weaned piglets

Background: Chitosan was used as an alternative to promote the growth of weaned piglets. And low-molecular- weight chitosan (LC) is one of chitosan derivatives and maintain beneficial biological properties of chitoson. The present experiment was carried out to examine the effects of LC on the growth performance, intestinal morphology, barrier function, cytokine expression, and antioxidant system of weaned piglets. Results: A total of 40 piglets weaned at 21 d of age, with average body weight 6.37 +/- 0.08 kg, were randomly assigned (5 pens/diet; 4 pigs/pen) to 2 treatments (a basal diet and the basal diet supplemented with 50 mg/kg LC) and were fed for 28 d. Compared with the control group, average daily feed intake (ADFI), and the expression of intestinal barrier protein ZO-1 was increased (P < 0.05) when the piglets fed the diet supplemented with LC. No significant differences were found in average daily gain (ADG, P > 0.05), gain-to-feed ratio (G:F, P > 0.05), the incidence of diarrhea (P > 0.05), or the antioxidant capacity (P > 0.05) between two groups. The expression of IL-1 beta and TNF-alpha in jejunal mucosa were significantly decreased (P < 0.05) in piglets fed the LC-supplemented diet in comparison to the control. Conclusion: The results of this study indicate that dietary supplementation with LC at 50 mg/kg was effective for enhancing the growth performance in weaned piglets, improving intestinal barrier function and alleviating intestinal inflammation.