Evaluation of fermentable oligosaccharides in diets fed to dogs in comparison to fiber standards

¹ Department of Animal Sciences, University of Illinois, Urbana, IL 61801

^* To whom correspondence should be addressed. E-mail: gcfahey{at}uiuc.edu.

	Abstract

Blends of fermentable oligosaccharides in combination with the non-fermentable fiber, cellulose, were evaluated for their ability to serve as dietary fibers in dog foods. Using a 6 x 6 Latin square design, six diets were evaluated that contained either no supplemental fiber, beet pulp, cellulose, or blends of cellulose, fructooligosaccharides (FOS), and yeast cell wall (YCW) added at 2.5% of the diet. Six ileal cannulated dogs were fed 175 g of their assigned diet twice daily. Chromic oxide served as a digestibility marker. Nutrient digestibility, fecal microbial populations, fermentative end-products, and immunological indices were measured. Total tract DM and OM digestibilities were lowest (P < 0.05) for the cellulose treatment. Crude protein digestibility was lower (P < 0.05) for the treatments containing carbohydrate blends. The cellulose treatment had the lowest (P < 0.05) concentration of bacteria and all diets containing fermentable fiber had greater (P < 0.05) fecal bifidobacteria concentrations compared to the diets without supplemental fermentable fiber. Lactobacilli concentrations tended to be greater (P < 0.08) in treatments containing fermentable fiber compared to the cellulose treatment. Bifidobacteria and lactobacilli concentrations were similar for the beet pulp treatment compared to the fermentable oligosaccharide blends. Total fecal short-chain fatty acid concentration was greater for the beet pulp treatment (P < 0.05) compared to the control and cellulose treatments. The treatments containing fermentable fiber had greater (P < 0.05) fecal butyrate concentrations compared to cellulose and control treatments. Immune indices were not affected by treatment. Our results suggest that dog foods containing blends of fermentable and non-fermentable carbohydrates produce similar physiological results as dog food containing beet pulp as a fiber source. Therefore, blends of these carbohydrates could be useful substitutes for beet pulp in dog foods.

Key Words: beet pulp, dietary fiber, dog, intestinal microbiota, oligosaccharides