Nucleotide plays an important role in the regulation of cellular energy and protein homeostasis. The objective of the current study was to investigate the cumulative effects of maternal supplementation with nucleotides in the form of uridine (UR) on fatty acids and amino acids constituents of neonatal piglets. A total of 52 pregnant sows with similar parity were assigned randomly and equally into the control (CON) group (fed a basal diet) or UR group (fed a basal diet with 150g/t UR). The experiment started on d 85 of gestation and ended on the day of delivery. The reproductive performance was recorded, and placenta, blood and liver samples of neonatal piglets were collected before consuming colostrum during farrowing. Results showed that supplementing with UR in sow’ diet significantly decreased the birth mortality of pigs (P = 0.05). In addition, maternal dietary UR supplementation increased serum total cholesterol (CHOL), high-density lipoprotein (HDL) and low-density lipoprotein (LDL) of neonatal piglets (P < 0.05). Moreover, the amino acid profile of serum and liver of neonatal piglets was affected by the addition of UR in sows’ diets (P<0.05). Furthermore, an up-regulation of mRNA expression of energy metabolism-related genes, including fatty acid elongase 5 (ELOVL5), fatty acid desaturase 1 (FADS1), hormone-sensitive lipase (HSL) and cholesterol- 7a-hydroxylase (CYP7a1), was observed in the liver of neonates from the UR group. Additionally, a decrease in placental gene expression of excitatory amino acid transporters 2 (EAAT2), excitatory amino acid transporters 3 (EAAT3), neutral AA transporter 1(LAT1) in UR group was concurrently observed (P<0.05), and higher protein expression of phosphorylated protein kinase B (P-AKT), raptor, peroxisome proliferator activated receptor α (PPARα) and PPARγ in placenta from UR group was also observed, (P<0.05). Together, these results showed that maternal UR supplementation could regulate the nutrients transport of placenta, largely in response to an alteration of mTORC1-PPARs signaling, thus regulating the nutrition metabolism of neonatal piglets, and improving reproductive performance.

In the present study, we aimed to evaluate the effects of maternal yeast-based nucleotide (YN) supplementation on the intestinal immune response and barrier function in neonatal pigs, as well as the diarrhoea rate and growth performance in suckling piglets. Sixty-four late-gestation sows were assigned to the following groups: the CON (fed a basal diet) and YN groups (fed a basal diet with 4 g YN/kg diet). The experiment started on d 85 of gestation and ended on d 20 of lactation. Diarrhoea rate and average daily gain of the piglets were recorded, and samples of blood and intestines from neonatal piglets were collected before they consumed colostrum during farrowing. Compared with the CON group, maternal YN supplementation increased the weaning weight of litter and decreased the diarrhoea rate ( P < 0.01). In addition, maternal YN supplementation promoted the ileal villus development in the neonates compared with that in the CON group ( P < 0.01). Maternal YN supplementation also increased the ileal secretory immunoglobulin A (sIgA) level compared with that in the CON group ( P < 0.05). The real-time PCR results showed that maternal dietary YN supplementation increased the jejunal and ileal expression of interleukin ( IL ) -17 , IL-8 , IL-1β , IL-10 and tumor necrosis factor ( TNF )- α in the neonates compared with that in the CON group ( P < 0.05). Overall, maternal nucleotide supplementation improved the villus development and innate immunity of neonatal piglets during late pregnancy. This may be associated with the decrease in diarrhoea and the increase in weaning weight of the litter of suckling piglets.