Low birthweight (LBW) neonates show impaired growth compared with normal birthweight (NBW) neonates. Glutamine supplementation benefits growth of weaning piglets, while the effect on newborn piglets is not sufficiently clear. We examined the effect of early neonatal glutamine supplementation on piglet growth, milk intake, and metabolic parameters. Sow-reared pairs of newborn LBW (0.8-1.2 kg) and NBW (1.4-1.8 kg) male piglets received glutamine (1 g · kg-1 body mass (BM) · day (d)-1; Gln-LBW, Gln-NBW; n=24/group) or isonitrogenous alanine (1.22 g · kg-1 BM · d-1; Ala-LBW; Ala-NBW, n=24/group) supplementation at 1-5 or 1-12 d of age (daily in 3 equal portions at 07:00, 12:00, 17:00 by syringe feeding). We measured piglet BM, milk intake (1, 11-12 d), plasma metabolite, insulin, amino acid (AA) and liver triglyceride concentrations (5, 12 d). The Gln-LBW group had higher BM (+7.5%, 10 d, P=0.066, 11-12 d, P<0.05) and milk intake (+14.7%, P=0.015) than Ala-LBW group. At 5 d, Ala-LBW group had higher plasma triglycerides (+34.7%, P < 0.1) and lower carnosine (-22.5%, P<0.05) than Ala-NBW and Gln-LBW, and higher liver triglycerides (+66.9%, P=0.029) than Ala-NBW. At 12 d, plasma urea was higher (+37.5%, P<0.05) with Gln than Ala supplementation. Several proteinogenic AA in plasma were lower (P<0.05) in Ala-NBW vs. Gln-NBW group. Plasma arginine was higher (P<0.05) in Gln-NBW vs. Ala-NBW piglets (5, 12 d). Supplemental glutamine moderately improved growth and milk intake and affected lipid metabolism in LBW piglets and AA metabolism in NBW piglets, suggesting potential effects on intestinal and liver function.
