Dietary l-arginine supplementation enhances porcine β-defensins gene expression in some tissues of weaned pigs

The present study was mainly conducted to test the hypothesis that dietary l-arginine supplementation regulates gene expression of β-defensins in some tissues of weaned pigs. Thirty crossbred piglets weaned at 21 days of age were allotted to 1 of 3 diets supplemented with 0.0, 0.5 and 1.0% l-arginine (10 pigs/treatment). Pigs consumed the diets for 7 d. On d 7, 6 pigs from each treatment were randomly killed, and the tissue and blood samples were collected. Compared with control pigs, dietary l-arginine supplementation did not affect the growth performance and serum concentrations of IgA, IgG, IgM, IL-1β, IL-2 and TNF-α (P>0.05), but dietary supplementation with 0.5% l-arginine reduced serum urea concentration (P<0.05). Additionally, dietary l-arginine supplementation significantly increased porcine β-defensin-1 gene expression of tongue, porcine β-defensin-3 gene expression of ileum and inguinal lymph node, and porcine β-defensin-2 gene expression of oral epithelium, tongue, ileum and inguinal lymph node (P<0.05). These results suggest that dietary supplementation with l-arginine enhances gene expressions of porcine β-defensins in some tissues of weaned pigs.