Physiology & Endocrinology - Livestock and Poultry: Endocrinology and Metabolism

To determine the effect of dietary brous ingredients on intestinal microbial population and activity, 48 early–weaned (24–25 days) pigs were divided into six dietary treatments: a standard diet (STD) based on corn, barley and soybean protein; or high brous diets obtained by replacing some major ingredients of STD with 8% Wheat bran (WB), 8% Wheat middlings (WM), 6% Sugar beet pulp (SBP), 4% Wheat bran and 3% Sugar beet pulp (WB–SBP), or 4% Wheat middlings and 3% Sugar beet pulp (WM–SBP). After 10 and 15 days receiving ad libitum the experimental diets, animals were weighed, sacriced, and digesta samples from the caecum, colon and rectum were taken. Short–chain fatty acid (SCFA) concentration was determined and microbial counts for enterobacteria and lactobacilli were determined by quantitative–PCR. Inclusion of WB promoted increases in the weight gain of the animals at day 15 (142, 1256, 136, 1164, 700, 1187 g for STD, WB, WM, SBP, WB–SBP, WM–SBP). Wheat bran, either at 8% or 4% promoted a decrease in enterobacteria counts in the caecum (11.1, 9.9, 11.7, 10.8, 8.2 and 11.6 log 16 S rDNA gene copies/g FM) and feces (10.3, 9.2, 11.5, 10.9, 8.7, 11.9 log 16 S rDNA gene copies/g FM for STD, WB, WM, SBP, WB–SBP, WM–SBP, respectively, P≤0.001) of piglets 15 days after weaning. No signicant differences were observed on the lactobacilli counts at d15 or on the microbial counts at d10. The SCFA concentrations increased significantly from d10 to d15 in the caecum and feces. Diets supplemented with SBP decreased the isoacids (isobutyrate and isovalerate) proportions in the caecum of piglets at day 10 after weaning (P≤0.003) and in the feces at day 15 post–weaning (P≤0.004), while the inclusion of WB signicantly increased the percentage of butyrate in the caecum at d15 (7.14, 14.22, 5.39, 4.63, 12.36, 11.48 % for STD, WB, WM, SBP, WB–SBP, WM–SBP, respectively, P≤0.001). Results suggest a benecial shift in the composition and activity of the hindgut microbial population of early weaned piglets fed on diets supplemented with WB.