Dose-Dependent Effects of Supplementing a Two-Strain Probiotic on Growth Performance, Blood Parameters, Fecal Metabolites, and Microbiome in Nursery Pigs.

This experiment was conducted to evaluate the effects of dietary supplementation level of a two-strain probiotic on growth performance, blood parameters, fecal metabolites, and microbiome in nursery pigs. A total of 54 weaned piglets were allotted to three treatments in three replicate pens with six pigs/pen for a 28 d feeding trial. The treatments were as follows: control: no probiotic supplementation; Pro1x: supplementation at 1.875 × 10 CFU/g diet; and Pro10x: supplementation at 1.875 × 10 CFU/g diet. Body weight at d 14 postweaning ( = 0.06) and average daily gain for d 0 to 14 postweaning ( < 0.05) were greater in the Pro1x treatment than in the other treatments. Blood glucose levels were greater in both probiotic treatments than in the control treatment at d 14 postweaning ( < 0.05). In the fecal short-chain fatty acid (SCFA) concentrations, the butyrate concentrations were greater in the Pro1x treatment than in the other treatments ( < 0.05), and the acetate, propionate, and total SCFA concentrations were greater in the Pro1x treatment than in the Pro10x treatment ( < 0.05). The beta diversity of fecal microbiome composition at d 14 postweaning based on Unweighted Unifrac analysis was dissimilar between the Pro1x and Pro10x treatments ( < 0.05). In conclusion, dietary supplementation of two strains selected to reduce effects of pathogenic to nursery diets at 1.875 × 10 CFU/g diet improved the growth rate in the early postweaning period, increased fecal SCFA concentrations and altered the fecal microbial community composition. A higher dose of did not improve the performance parameters over those of the control piglets.