Effect of dietary fiber and tributyrin on nursery pig health, performance, bacteriome, and volatile fatty acid concentration.

Dietary fiber and volatile fatty acid (VFA) metabolites have been shown to improve intestinal health and reduce post-weaning diarrhea in pigs. Therefore, the current study was conducted to evaluate the impact of insoluble and soluble dietary fiber sources and butyrate on the intestinal health and growth performance of nursery pigs. It was hypothesized that insoluble and soluble dietary fiber sources or butyrate supplementation would improve nursery pig performance and enteric health. Over two replicates, a total of 610 weaned pigs were assigned to one of five dietary treatments (n = 17 pens/treatment): 1) control diet (CON), 2) wheat bran (WB), 3) beet pulp (BP), 4) corn distiller's dried grains with solubles (DDGS), and 5) CON plus 0.20% tributyrin. Diets were fed in two phases (14 and 28 days). Pigs were confirmed positive for rotavirus A, B, and C and F18 enterotoxigenic Escherichia coli (E. coli). There was no effect of dietary fiber or tributyrin on the proportion of pigs with normal, soft, or liquid fecal consistency in weeks 1, 2, or 3 of the study (P > 0.10). There were no significant differences in average daily gain (ADG), average daily feed intake (ADFI), or gain-to-feed ratio (G:F) among treatments in phase 1 (P > 0.10). Tributyrin tended to increase ADFI in phase 2 compared to CON and BP (P = 0.063), and increased ADFI overall compared to CON (P = 0.031), but had no significant effect on final body weight (P > 0.10). Dietary treatment did not affect ileal, colonic, or fecal VFA concentrations on days 7, 10, or 42. However, on day 22, CON pigs had greater fecal acetate, propionate, valerate, and total VFA concentrations than one or more fiber treatments (P < 0.05), with butyrate tending to be greater than WB (P = 0.080). Bacterial community analysis revealed no effect of dietary fiber treatment on alpha diversity, except for DDGS, where day 14 and day 42 communities differed (P = 0.014). Beta-diversity analysis identified distinct clustering between time points (P = 0.001) and between treatments (P = 0.024) using the Bray Curtis dissimilarity matrix. Overall, although bacterial community composition was affected, the inclusion of wheat bran, beet pulp, corn DDGS, or tributyrin did not significantly impact intestinal health, pathogen load, VFA concentration, or growth performance in nursery pigs.