The effects of dietary sulfur amino acids on serum biochemical variables, mucosal amino acid profiles, and intestinal inflammation in weaning piglets

Abstract

Sulfur amino acids (SAAs) play critical roles in biological functions and protection against diseases. The present study was conducted to investigate the impact of dietary SAAs on serum biochemical variables, jejunal mucosal amino acid contents, and intestinal inflammation in weaned piglets. Forty Duroc × Landrace × Yorkshire piglets at 21 days of age were weaned and randomly assigned to one of five diets that contained 0.53, 0.63, 0.74, 0.85, or 0.96% SAAs, which corresponded to 70, 85, 100, 115, or 130% of the SAAs: Lysine (Lys) ratio recommended by National Research Council (NRC, 2012). Dietary supplementation with SAAs significantly enhanced (P < 0.05) serum creatinine and low density lipoprotein. Serum glucose was reduced (P < 0.01) and there was a tendency of decrease for total cholesterol (TC; P = 0.052) and triglycerides (TG; P = 0.069) in response to dietary SAAs supplementation. No significant difference was observed in jejunal mucosal amino acid profiles, but dietary supplementation with SAAs lowered (P < 0.05) jejunal composition of Ala and tended to decrease the composition of His (P = 0.090). Dietary supplementation with 0.63% or more SAAs reduced (P < 0.05) the mRNA expression of genes involved in SAAs metabolism (NSF1 and CBS), as well as genes related to inflammation (TNF-a, TGF-β, and IL-1β). These results indicate that dietary SAAs may involve in regulating lipid metabolism and intestinal inflammation of weaning piglets.