NUTRIENT DIGESTION BY ILEAL CANNULATED DOGS AS AFFECTED BY DIETARY-FIBERS WITH VARIOUS FERMENTATION CHARACTERISTICS

We studied the effects of dietary fibers with various fermentation cha racteristics on nutrient digestion at the distal ileum and in the tota l tract of dogs. The following high-protein (34%), highfat (23%) diets were fed: 1) a control treatment (CON) with 0% supplemental fiber; 2) beet pulp (BP), 7.5%; 3) low-cellulose mixture (LCM), 2.5% cellulose + 5.0% pectin; 4) high-cellulose mixture (HCM), 5.0% cellulose + 2.5% pectin; or 5) Solka Floc (R) (SF), 7.5% cellulose. Nutrient intakes by fiber-supplemented dogs were similar among treatment groups but great er (P <.05) than for dogs fed the control diet. Digestion of nutrients at the distal ileum was similar among groups except for fat: the dogs fed BP digested less fat than those fed the other sources of dietary fiber. Digestion of amino acids at the distal ileum was similar for al l groups, except for lysine, which increased(P <.05) in digestibility as dietary cellulose concentration increased. Dogs consuming LCM had l ower apparent ileal digestibility values for all nutrients, including most amino acids, than dogs consuming HCM or SF. Total tract digestion of DM and OM by dogs fed supplemental fiber was less (P <.05) than fo r dogs fed the control diet. The BP treatment was higher than other fi ber treatments in total tract digestion of OM (P <.10) and total dieta ry fiber (P <.05). Total tract digestibilities of all nutrients exhibi ted either linear or quadratic responses to dietary cellulose concentr ations. Apparent ileal and total tract nutrient digestion was influenc ed by the source of dietary fiber consumed.