Source of dietary fiber fed to dogs affects nitrogen and energy metabolism and intestinal microflora populations

Abstract

Twenty-eight adult ovariohysterectomized dogs were fed one of four diets differing in type of dietary fiber to assess the effects of fiber on energy digestibility, partitioning of nitrogen (N) components, and changes in intestinal microflora. Dietary fiber sources were beet pulp (BP), short-chain fructooligosaccharides (FOS), cellulose (C) and a fiber blend (FB; BP, gum talha, and FOS). Dry matter (DM) intake was reduced and DM digestibility was increased for dogs fed the FOS diet. Fecal N and microbial N excretion (g/day) was greater with the FB diet. This diet tended to reduce urinary N excretion. Bacterial characterization of intestinal contents found that FOS increased total aerobic bacteria in the distal colon. Fiber Blend decreased counts of Clostridium spp. in the ileum. We concluded that fermentable fiber sources increase microbial growth in the colon, and have the potential to trap and remove N from the body.