217 Comparative Effects of Dietary Methionine and Cysteine Supplementation on Redox Status and Intestinal Integrity in Immunologically Challenged-weaned Pigs

Abstract

The aim was to investigate the effects of dietary Met and Cys supplementation in immunologically challenged-weaned pigs. Forty weaned piglets (6.51 ± 0.29 kg) were randomly allocated to five treatments and fed the assigned diets for 9 days. The treatments included: (1) sham-challenged control (SCC), (2) challenged control (CC), (3) MET (CC + 0.1% DL-Met supplementation), (4) CYS (CC + 0.1% L-Cys supplementation), and (5) MET+CYS (CC + 0.1% DL-Met and 0.1% L-Cys supplementation). Piglets were intramuscularly injected with either lipopolysaccharides (LPS; 30 μg/kg) or saline solution on day 7. All data were analyzed using single degree of freedom contrasts in the mixed procedure of SAS to test the effect of LPS challenge, Met supplementation, Cys supplementation, and Met × Cys supplementation. The CC group had lower (P < 0.05) villi height and villi surface area and glutathione (GSH) concentration and higher (P < 0.05) flux of 4-kDa fluorescein isothiocyanate dextran (FD4) in the jejunum than SCC group. Dietary Cys supplementation increased (P < 0.05) villi surface area, GSH concentration and reduced GSH: oxidized GSH and decreased (P < 0.05) the flux of FD4 in the jejunum. Dietary Met supplementation enhanced (P < 0.05) hepatic GSH content. Pigs in the MET group had greater mRNA abundance of IL-6 and IL-10 (P < 0.05) and lower serum IL-8 concentration than those in the CC group. There were Met × Cys interactions (P < 0.05) in serum IL-4 and IL-8 concentrations and hepatic Trolox equivalent antioxidant capacity. In conclusion, dietary L-Cys supplementation restored intestinal integrity and GSH concentration that were affected by LPS challenge. Dietary DL-Met supplementation improved hepatic GSH and reduced systemic inflammatory response, but antagonistic interaction with dietary Cys supplementation was observed in inflammatory response and redox status.