Supplemental effects of dietary nucleotides on intestinal health and growth performance of newly weaned pigs

Intestinal challenges upon weaning would increase the needs of nucleotides for enterocyte proliferation, whereas de novo synthesis maybe insufficient. This study aimed to evaluate supplemental effects of dietary nucleotides on intestinal health and growth performance in newly weaned pigs. Fifty newly weaned pigs (19-d-old, 25 barrows and 25 gilts, 4.76 0.42 kg BW) were individually housed and allotted to 5 treatments with increasing nucleotide supplementation (0, 50, 150, 250, and 500 mg/kg) based on a randomized complete block design with the initial BW and sex as blocks. Dietary nucleotides were provided from YT500 (Hinabiotech, Guangzhou, China). Pigs were fed for 21 d based on 2 phases (phase 1: 11 d and phase 2: 10 d) and experimental diets were formulated to meet or exceed nutrient requirements su ested by NRC (2012). Feed intake and BW were recorded. Titanium oxide (0.4%) was added as an indigestible marker from day 17. Plasma collected on day 18 was used to measure tumor necrosis factor-u (TNF-u), interleukin-6 (IL-6), and malondialdehyde (MDA). Pigs were euthanized on day 21 to collect tissues to evaluate TNF-a, IL-6, MDA, morphology, and crypt cell proliferation rate in the jejunum. Ileal digesta were collected to measure ileal nutrient digestibility. Data were analyzed using contrasts in the MIXED procedure of SAS. Nucleotide supplementation increased (P < 0.05) ADFI in phase 1. Nucleotide supplementation at 50 and 150 mg/kg increased (P < 0.05) ADG in phase 1, whereas increased (P < 0.05) ADFI and tended to increase (P = 0.082) ADG in overall. Increasing nucleotide supplementation changed (quadratic, P< 0.05) villus height-crypt ratio (at 247 mg/kg) and decreased (linear, P < 0.05) crypt cell proliferation rate in the jejunum. Increasing nucleotide supplementation reduced (P < 0.05) jejunal IL-6 (at 50 and 150 mg/kg) and tended to change (quadratic, P = 0.074) plasma MDA (at 231 mg/kg). Nucleotide supplementation at 50 and 150 mg/kg increased (P < 0.05) ileal digestibility of energy and ether extract. In conclusion, nucleotide supplementation at a range of 50 to 250 mg/kg in the diets seems to be beneficial to newly weaned pigs by enhancing growth performance possibly due to reduced intestinal inflammation and oxidative stress as well as improved intestinal villi structure and energy digestibility.