Dietary supplementation with N-carbamylglutamate increases the expression of intestinal amino acid transporters in weaned Huanjiang mini-pig piglets1

Weaning is associated with reduced intestinal absorptive capacity in piglets. Our previous study indicated that dietary supplementation with N-carbamylglutamate (NCG) enhanced growth performance and improved intestinal function in weaned piglets. The present study was conducted to test the hypothesis that dietary supplementation with NCG may increase the growth performance of weaned piglets by regulating the expression of intestinal nutrient transporters, thus enhancing nutrient absorption. Twenty-four Huanjiang mini-pig piglets weaned at 21 d of age (3.17 ± 0.21 kg average BW) were randomly assigned to 2 dietary treatments consisting of a basal diet and the basal diet with 0.1% NCG supplementation for a 14-d period with 6 pens per treatment and 1 male and 1 female per pen. On d 14, 1 piglet was randomly selected from each pen for blood and tissue sampling. Dietary NCG supplementation enhanced (P < 0.05) growth rate and the efficiency of feed use in weaned Huanjiang mini-pig piglets. The NCG-supplemented diet increased (P < 0.05) mRNA expression levels of Slc6a19, Slc7a9, and Slc1a1 and the protein abundance of ASCT2, B(0)AT1, b(0,+)AT, y(+)LAT1, and EAAC1 in the jejunum. Furthermore, the contents of low density lipoprotein, ammonia, urea nitrogen, and AA as well as the activity of alkaline phosphatase in plasma were all altered (P < 0.05) by supplementation with NCG. These findings indicate that dietary supplementation with NCG may improve intestinal absorptive function in weaned piglets by increasing the expression of AA transporters in the intestine.