Effect of Maternal Probiotic and Piglet Dietary Tryptophan Level on Performance and Piglet Intestinal Health Parameters Pre-Weaning

A 2 × 3 factorial design was used to examine the effects of maternal probiotic supplementation (<i>Bacillus subtilis</i> and <i>Bacillus amyloliquefaciens</i>) and/or piglet dietary Trp levels on sow performance and fecal microbiota composition, as well as offspring pre-weaning performance and intestinal health parameters on the day of weaning. On day 83 of gestation, 48 sows were allocated to either: (1) control, or (2) control + probiotic (1.1 × 10⁹ colony forming units/kg of feed). Their litters were assigned to 0.22, 0.27, or 0.33% standardized ileal digestible (SID) Trp diets (0.17, 0.21 and 0.25 SID ratio of Trp to lysine (Trp:Lys), SID lysine = 1.3%). At weaning, one piglet per litter was sacrificed for intestinal health analysis. Diet had no effect on sow reproductive or offspring growth performance pre-weaning (<i>p</i> > 0.05). Maternal probiotic supplementation led to distinct microbial communities in the sow feces on day 114 of gestation, increasing the relative abundance of <i>Anaerocella</i> and <i>Sporobacter</i>, while decreasing <i>Lactobacillus</i>, <i>Ruminococcus</i>, and <i>Christensenella</i> (<i>p</i> < 0.05). In the offspring colonic digesta, maternal probiotic supplementation increased <i>Dorea</i>, <i>Sporobacter</i>, and <i>Anaerobacterium</i>, while reducing the potentially harmful phylum Proteobacteria, specifically the family Enterobacteriaceae (<i>p</i> < 0.05), with a tendency for a reduction in the genus <i>Escherichia</i> (<i>p</i> < 0.1). Maternal probiotic supplementation enhanced duodenal morphology and modulated the expression of genes in the ileum, including a downregulation of certain immune and barrier defense genes (<i>p</i> < 0.05). Piglets from probiotic sows had reduced branch chain fatty acids (BCFA) in the cecal digesta and an increase in the total VFA and acetate in the colonic digesta (<i>p</i> < 0.05). There were limited effects of Trp level in the offspring's creep diet or maternal × creep interactions, though this analysis was likely confounded by the low creep feed intake (total of ~0.83 kg/litter).