The present study was conducted to test the hypothesis that dietary supplementation with a nano chitosan-zinc complex (CP-Zn, 100 mg/kg zinc) could alleviate weaning stress in piglets challenged with ETEC K88 by improving growth performance and intestinal antioxidant capacity. The in vivo effects of CP-Zn on growth performance variables (including gastrointestinal digestion and absorption functions and the levels of key proteins related to muscle growth) and the antioxidant capacity of the small intestine were evaluated in 72 weaned piglets. The porcine jejunal epithelial cell line IPEC-J2 was used to further investigate the antioxidant mechanism of CP-Zn in vitro. The results showed that CP-Zn supplementation ... More
The present study was conducted to test the hypothesis that dietary supplementation with a nano chitosan-zinc complex (CP-Zn, 100 mg/kg zinc) could alleviate weaning stress in piglets challenged with ETEC K88 by improving growth performance and intestinal antioxidant capacity. The in vivo effects of CP-Zn on growth performance variables (including gastrointestinal digestion and absorption functions and the levels of key proteins related to muscle growth) and the antioxidant capacity of the small intestine were evaluated in 72 weaned piglets. The porcine jejunal epithelial cell line IPEC-J2 was used to further investigate the antioxidant mechanism of CP-Zn in vitro. The results showed that CP-Zn supplementation increased the jejunal villus height and decreased the diarrhoea rate in weaned piglets. CP-Zn supplementation also improved growth performance (ADG and ADFI), increased the activity of carbohydrate digestion-related enzymes (amylase, maltase, sucrase and lactase) and the mRNA expression levels of nutrient transporters (SGLT1, GLUT2, PEPT1 and EAAC1) in the jejunum, and upregulated the expression levels of mTOR pathway-related proteins (IRS1, phospho-mTOR and phospho-p70S6K) in muscle. In addition, CP-Zn supplementation increased glutathione content, enhanced T-SOD and GSH-px activity, and reduced MDA content in the jejunum. Furthermore, CP-Zn decreased the content of MDA and ROS, enhanced the activity of T-SOD and GSH-px, and upregulated the expression levels of Nrf2 pathway-related proteins (Nrf2, NQO1 and HO1) in LPS-stimulated IPEC-J2 cells. Collectively, these findings indicate that CP-Zn supplementation can improve growth performance and the antioxidant capacity of the small intestine in piglets, thus alleviating weaning stress.
