DIETARY FIBER FOR CATS - IN-VITRO FERMENTATION OF SELECTED FIBER SOURCES BY CAT FECAL INOCULUM AND IN-VIVO UTILIZATION OF DIETS CONTAINING SELECTED FIBER SOURCES AND THEIR BLENDS

Two experiments were conducted to evaluate the addition of single sour ces and blends of dietary fibers to cat diets. In Exp. 1, fermentabili ty of selected fibrous substrates by cat fecal microflora was evaluate d. After 24 h of fermentation, OM disappearance (OMD) and total short- chain fatty acid (SCFA) production were greatest (P <.05) for citrus p ectin, guar gum, and locust bean gum, whereas Solka Floc(R) resulted i n the least (P <.05) OMD and total SCFA production. In Exp. 2, six die ts were formulated based on results of Exp. 1. The highest (P <.05) di gestibilities of DM and OM occurred when cats consumed the diet with n o supplemental fiber, and the lowest (P <.05) digestibilities occurred when cats consumed the SCFA blend (SC) diet. Nitrogen and lipid diges tibilities also were lowest(P <.05) for cats consuming the SC diet, wh ereas total dietary fiber (TDF) digestibility (P <.05) was greatest fo r cats consuming the beet pulp, SC, and combination blend diets. Fecal consistency scores were highest (P <.05) for cats consuming the SC di et, indicating liquid, unformed stools. In conclusion, the in vitro fe rmentation technique was reasonably accurate in predicting in vivo dig estion of fiber. The SC diet, which contained the most fermentable fib ers, severely decreased nutrient digestibility and resulted in poor st ool characteristics. Diets that contain moderately fermentable fiber p rovide fermentation end products that may be important in maintaining the health of the gastrointestinal tract of the cat.