Previous studies have shown that maternal
resveratrol improved growth performance and altered the microbial composition of suckling piglets under hot summer conditions. However, it remains unclear how maternal
resveratrol improves growth performance of suckling piglets during high summer temperatures. A total of 20 sows (Landrace × Large White; three parity) were randomly assigned to 2 groups (with or without 300 mg/kg
resveratrol) from d 75 of gestation to d 21 of lactation during high ambient temperatures (from 27 to 30 °C). The results showed that maternal
resveratrol supplementation increased total daily
weight gain of piglets under hot summer conditions, which is consistent with previous studies. Furthermore, we found that maternal
resveratrol improved the intestinal morphology and intestinal epithelial proliferation in suckling piglets. Dietary
resveratrol supplementation affected the characteristics of exosome-derived
microRNAs (
miRNAs) in sow colostrum, as well as the genes targeted by differentially produced
miRNAs.
MiRNAs are concentrated in the tight junction pathway. As a result, the expression of intestinal
tight junction proteins was increased in suckling piglets (P < 0.05). Notably, maternal
resveratrol increased the intestinal
secretory immunoglobulin A (
sIgA) levels of suckling piglets via colostrum immunoglobin (P < 0.05), which could increase the abundance of beneficial microbiota to further increase the concentration of
short chain fatty acids (SCFA) in suckling piglets' intestine (P < 0.05). Finally, our correlation analysis further demonstrated the positive associations between significantly differential intestinal microbiota, intestinal
sIgA production and SCFA concentrations, as well as the positive relation between total daily
weight gain and intestinal health of suckling piglets. Taken together, our findings suggested that maternal
resveratrol could promote intestinal health to improve piglet growth during high summer temperatures, which might be associated with the immunoglobin and exosome-derived
miRNAs in sows' colostrum.