Effect of N-Carbamylglutamate Supplementation on Growth Performance, Jejunal Morphology, Amino Acid Transporters, and Antioxidant Ability of Weaned Pigs

SIMPLE SUMMARY: NCG is a structural analogue of NAG, and can activate the rate-limiting enzyme of arginine synthesis and promote the synthesis of endogenous arginine in the intestine. Recent studies have found that NCG plays an important role in improving growth performance and maintaining intestinal health. However, there are few reports on the effects of NCG on the intestinal development and antioxidant capacity of piglets. The aim of this study was to investigate the effects of dietary NCG supplementation on the growth performance, apparent nutrient digestibility, jejunal morphology, amino acid transporters, and antioxidant capacity of weanling piglets. Studies have shown that dietary NCG supplementation can improve the growth performance and intestinal antioxidant capacity of weaned piglets. ABSTRACT: Weaning is an important period that affects the performance of piglets. However, the regulation of dietary amino acid levels is considered to be an effective way to alleviate the weaning stress of piglets. N-carbamylglutamate (NCG) plays an important role in improving the growth performance and antioxidant capacity of animals. A total of 36 weaned piglets were randomly assigned to two treatment groups, a control group (CON) and a 500 mg/kg NCG group (NCG), and the experiment lasted for 28 days. The results show that the NCG treatment group showed an increased 0–28 days average weight gain and average daily feed intake, and also increased contents of GLU and HDL, and lower SUN in serum, and an upregulation of the expression of the amino acid transporters SNAT2, EAAC1, SLC3A1, and SLC3A2 mRNA in the jejunum (p < 0.05), as well as an increased villus length and VH:CD ratio, and claudin-1, occludin, and ZO-1 mRNA expression in the jejunum (p < 0.05). The NCG treatment group showed an increased content of GSH-Px in serum and T-AOC and SOD in the jejunum, and a lower content of MDA (p < 0.05); and the upregulation of the mRNA expression related to antioxidant enzymes (CAT, SOD1, Gpx4, GCLC, GCLM and Nrf2, AhR, CYP1A1) in the jejunal mucosa (p < 0.05). In addition, compared with the control group, the NCG treatment group saw an upregulation in the mRNA expression of IL-10 and a decrease in the expression of IL-1β and IL-4 in the jejunal mucosa (p < 0.05). In summary, the results of this study suggest that NCG improved growth performance and jejunal morphology, improved the jejunal transport of amino acids related to the ornithine cycle, and improved the antioxidant capacity in weaned pigs.