The Influence of Dietary Fiber on Digestibility, Rate of Passage and Gastrointestinal Fermentation in Pigs

Abstract

Twenty mature Yorkshire pigs were fed diets containing coarse bran, fine bran, alfalfa or cellulose (Solka floe) and the effects of these sources of fiber on large intestinal microflora, digestibility and rate of passage were investigated. An in vitro batch microbial culture system was used with fecal, cecal, upper large intestinal and lower large intestinal inocula to measure cell wall indigestibility and VFA production with the same (above) sources of fiber. In this system, composition of fiber that the pigs were consuming had a significant effect on cell wall indigestibility and VFA production. The quantities of VFA produced in vitro were significantly affected by composition of the substrates. The VFA concentrations in fresh feces were significantly affected by the dietary fiber consumed. The VFA concentrations were lower (P<.05) in the lower large intestine than in the cecum and upper large intestine. No difference in cell wall indigestibility was observed among the different areas of inoculum origin. Digestibilities of dry matter, cell wall, cellulose, hemicellulose and protein were affected (P<.05) by source of dietary fiber. Similarity, dietary fiber had a significant effect on large intestinal turnover time. Results are discussed in relation to similar research with human subjects. Copyright © 1982. American Society of Animal Science. Copyright 1982 by American Society of Animal Science.