Dietary supplementation with yeast product improves intestinal function, and serum and ileal amino acid contents in weaned piglets

highlights
• Yeast products affected serum biochemical variables of weaned piglets.
• Yeast products enhanced mucosal SIgA contents in intestine of weaned piglets.
• Yeast products affected serum and intestinal amino acids contents of weaned piglets.
• Yeast products enhanced ileal alkaline phosphatase activity of weaned piglets.
• Yeast products regulated intestinal amino acid transporters expression.

Weaning is associated with impairments in intestinal and immune function, and dietary supplementation with yeast products can improve the intestine mucosal structure and stimulate the immune system of weaned piglets. The present study was conducted to test the hypothesis that dietary supplementation with yeast product may regulate immunoglobulin production by improving intestinal function and nutrient levels in weaned piglets. Eighteen piglets weaned at 21 days of age were randomly assigned to receive 1 of 3 treatments consisting of a basal diet (control), the basal diet supplemented with 1.2 g/kg of yeast product (yeast product) or the basal diet supplemented with 20 mg/kg of colistin sulphate (antibiotic) for 14 days. Dietary yeast product or antibiotic supplementation enhanced (P<0.05) duodenal and ileal mucosal sIgA as well as serum total protein, IgG, and IgM contents in weaned piglets. Piglets that were fed a diet that contained yeast product had greater (P<0.05) serum Ile, Leu, Phe, and Pro contents than control piglets. The contents of Arg, His, Leu, Lys, Trp, Val, Ser, Glu, Gln, and Pro in the ileal mucosa of weaned piglets were also increased (P<0.05) when yeast products were included in the diet. Consistent with the increases in amino acid (AA) contents, the activity of alkaline phosphatase and the expression of AA transporters were both increased (P<0.05) in the ileum of piglets that were fed a diet that contained yeast product. These findings indicate that yeast product may enhance immunoglobulin production by improving intestinal function and the levels of nutrients in weaned piglets, which suggests that yeast product might be an alternative to the use of antibiotics in diets for weaning piglets.