Utilization of selected dietary fibers by dogs and cats

Several experiments with dogs and cats were designed to evaluate the fermentative properties of selected fiber sources, the efficacy of including various fibers in dog and cat diets, and to evaluate factors that may influence the fermentative activity of intestinal microflora. In vitro fiber fermentation with dog fecal microflora indicated least fermentation occurred for Solka Floc{dollar}spcircler{dollar} and oat fiber while greatest fermentation occurred for fructooligosaccharides, lactulose, citrus pectin, and guar gum. In vitro fiber fermentation with cat fecal microflora indicated least fermentation of Solka Floc{dollar}spcircler{dollar} while citrus pectin, guar gum, and locust bean gum resulted in greatest fermentation. In vitro results were used to formulate diets containing fibers with different expected amounts of fermentation and stool consistency. Dogs and cats fed a diet containing a blend of fibers formulated to be highly fermentable resulted in poor stool consistency. Cats consuming a diet that contained a blend of fibers formulated to be highly fermentable not only resulted in poor stool consistency but also severely depressed nutrient digestibility. Dogs and cats that consumed diets containing moderately fermentable fibers maintained nutrient digestibility and resulted in desirable stool characteristics. The effect of providing fermentable fiber to dogs and cats on the fermentative activity of intestinal microflora also was evaluated. In vitro substrate fermentation was increased with fecal microflora from dogs and cats fed a diet containing a moderately fermentable fiber compared to fecal microflora from dogs and cats fed diets containing little fermentable fiber. These results suggest that fermentable fiber can increase the fermentative activity of intestinal microflora. A final experiment was designed to compare the fermentative activity of intestinal microflora from cats and dogs to microflora from other species with known abilities to utilize fiber. Results indicated that substrate fermentation is not only influenced by the fermentative activity of microflora but also by other factors such as fermentation lag time and digesta passage rate. In conclusion, intestinal microflora from dogs and cats can ferment certain sources of dietary fiber. Production of short-chain fatty acids from fiber fermentation may be important in promoting gut health of the dog and cat.