The effect of volatile fatty acid inclusion in drinking water on intestinal microflora, VFA, pH, dry matter, and performance in weanling pigs

In a series of three 17 d replicate trials, a total of 36 ileal cannulated pigs were used to determine the effects of volatile fatty acid (VFA) inclusion in drinking water on ileal microflora, hemolytic Escherichia coli, VFA concentrations, pH, dry matter (DM), and pig performance. All pigs were weaned at 21 d-of-age and assigned to one of three treatments including: Tl) ad libitum access to water, T2) ad libitum access to water containing acetate (50mM), propionate (5mM), and butyrate (3mM), and T3) ad libitum access to water containing acetate (25mM), propionate (2.5mM), and butyrate (1.5mM). Individual water intake was measured daily and feed intake was measured twice weekly. All pigs were individually caged in an environmentally controlled room with ad libitum access to a phase starter diet. Ileal samples were collected at 21, 24, 28, 31, 35, and 38 d-of age. At 38 d-of-age, pigs were sacrificed and contents were collected from the stomach, duodenum, ileum, cecum, and spiral colon. Digesta were analyzed for total E. coli, streptococci, lactobacilli, VFA, pH, and DM. Neither water nor feed intake differed between treatments and no differences were observed in microflora concentrations between treatments. Average ileal E. coli concentrations of 6.23, 5.87, and 6.15, streptococci concentrations of 7.55, 7.39, and 7.34, and lactobacilli concentrations of 7.32, 7.49, and 7.15 log₁₀; CFU/g were observed for Tl, T2, and T3 pigs, respectively. Time (day) effects (P = .0001) were observed for E.coli, streptococci, and lactobacilli. Additionally, VFA concentrations were unaffected by treatment; however, day effects were observed (P = .0001). Treatment had no effect on ileal pH or DM; however, pH was observed to increase (P = .0001) by day 3 postweaning for all treatments. Furthermore, treatment had no effect on pH in the various gastrointestinal sites. Results indicate that VFA inclusion in drinking water had no significant effect on ileal microflora, VFA, pH, DM, or performance in weanling pigs.