EFFECTS OF DIETARY FIBER ON DIGESTION, BLOOD PLASMA LIPIDS AND GASTROINTESTINAL TRACT PARAMETERS IN NONRUMINANTS

Scope of Study. Five experiments (Chapters III-V) were conducted to determine the effect of dietary fiber source and level on digestibility, gastrointestinal tract parameters and blood plasma lipids in nonruminants. In the first experiment, chicks were fed two semi-purified fiber sources, psyllium seed and Solka floc, and one inert source of bulk (polyethylene) to determine the effects of fiber composition and level on feed intake, weight gain, rate of digesta passage and intestinal tract weight. In experiment 2, eight natural fiber sources were fed to determine the effects of fiber source on feed intake and weight gain. Experiment 3 utilized barrows with T-cannulas in the distial ileum to determine the effect of semi-purified fiber sources: psyllium seed, guar gum, solka floc and Indulin (IN), a source of lignin, on the site and extent of digestibility. Experiment 4 consisted of feeding sows diets containing 25 percent beet pulp and wheat bran to evaluate the influence of fiber on blood plasma lipids and cecal parameters. In experiment 5, digestibility of beet pulp and wheat bran were determined using barrows with T-cannulas in the distal ileum.;Findings and Conclusions. The results of trial 1 indicate that dietary fiber does not act as an inert ingredient. Chicks fed increasing levels of Solka floc and psyllium seed did not increase intake sufficiently to maintain energy intake and weight gain declined. In the second trial, natural fiber sources differed in their affect on feed intake, digestibility and weight gain; indicating that fiber sources found in typical feedstuffs will effect feed intake and weight gain. In the third experiment fiber components composed of noncellulosic polysaccharides decrease post-ileal digestibility of dietary components. Cecal volume and weight of sows fed beet pulp but not wheat bran were increased in trial 4, when compared to those fed the control diet. Plasma cholesterol levels were not decreased by the addition of 25% beet pulp or wheat bran to the control diet. Pre-cecal dry matter and crude protein digestibility were reduced in pigs fed 25% beet pulp diets. These results indicate that noncellulosic polysaccharides influence the percent and site of digestibility in nonruminants.