[Show abstract][Hide abstract] ABSTRACT: Diets containing soluble NSP (sNSP) and resistant starch (RS) increase hindgut fermentation in pigs, which in turn increases the incidence of swine dysentery (SD) after infection with the intestinal spirochaete Brachyspira hyodysenteriae. In the present study pigs were fed diets based on either wheat or sorghum, fed either raw or treated by extrusion, and/or with the addition of dietary enzymes to reduce RS and/or sNSP content. The aim was to determine the effects of these treatments on pig performance, large intestinal fermentation and expression of SD. Weaned pigs (n 132) were fed experimental diets for 4 weeks, when half the pigs in each treatment group were euthanased and samples collected to assess the influence of the diet on hindgut fermentation. The remaining pigs then were infected with B. hyodysenteriae, and monitored for development of SD. In general, compared with pigs fed raw wheat, fermentation in all parts of the large intestine was reduced either by feeding raw sorghum-based diets, or by feeding diets that were extruded. The addition of enzymes that degrade RS or sNSP reduced fermentation only in the distal parts of the large intestine. The incidence of SD was lower in pigs fed sorghum-based diets, and some of the extruded diets, but none of the dietary treatments offered full protection against SD. Multiple regression analysis of the results from all three experiments showed that colonisation by spirochaetes was highly related to dietary sNSP concentrations, whilst development of SD was similarly influenced by RS content of the diet.
British Journal Of Nutrition 09/2002; 88(2):159-69. DOI:10.1079/BJNBJN2002607 · 3.34 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A study was made of dietary influences on the large intestinal microbiota of pigs and on the incidence of swine dysentery (SD) after experimental infection with Brachyspira hyodysenteriae, the aetiological agent of SD. Animals were fed diets based either on wheat (expts 1 and 2) or sorghum (expt 2). Grains were ground and fed either raw or after high temperature and pressure extrusion and/or after addition of exogenous enzymes to the whole diet to reduce the starch and soluble non-starch polysaccharides available for fermentation in the large intestine. Limiting fermentation creates conditions that apparently reduce the incidence of SD after infection with B. hyodysenteriae. The diets were fed to weaned pigs for 4-6 weeks, then half the animals on each diet were killed and gut samples collected for microbiology. The treatments had little effect on bacterial numbers. In expt 1, dietary extrusion of wheat reduced lactobacilli in the large intestine. Addition of enzymes to extruded wheat-based diets in expt 2 reduced facultative anaerobes and increased non-sporing anaerobes. Addition of enzymes to a raw sorghum diet in expt 3 decreased numbers of facultative anaerobes, while extrusion of sorghum increased total anaerobes. Bacteroides spp. and Fusobacterium spp., which act in synergy with B. hyodysenteriae in SD, were isolated at a higher percentage in pigs fed the untreated wheat diet than in pigs fed the treated wheat diets. Following experimental infection the incidence of SD amongst pigs fed treated wheat diets was slightly lower than those fed the untreated diet, but with sorghum-based diets the opposite was found. Overall, the different dietary treatments used did not significantly reduce SD.