A. R. Patil

Nutrient digestibilities, microbial populations, and protein catabolites as affected by fructan supplementation of dog diets

Fructans are fermentable carbohydrates and include short-chain fructooligosaccharides (scFOS), inulin, and hydrolyzed inulin (oligofructose, OF). Two studies with dogs were designed to examine the effects of low concentrations of fructans on nutrient digestibilities, fecal microbial populations, and endproducts of protein fermentation, and fecal characteristics. In Exp. 1, 11 adult male beagles were fed corn-based, kibbled diets supplemented with or without OF to provide 1.9 +/- 0.6 g/d. Dietary inclusion of OF decreased (P < 0.05) nutrient digestibilities, but did not affect fecal characteristics. Increasing OF concentration tended (P < 0.06) to linearly decrease fecal ammonia concentrations, but not those of branched-chain fatty acids (BCFA), amines, indole, or phenols. Fecal concentrations of total short-chain fatty acids (SCFA) and butyrate tended to be higher in OF-supplemented dogs (P < 0.10), as was the ratio of bifidobacteria to total anaerobes (P = 0.15). In Exp. 2, ileally cannulated adult female hounds were fed a meat-based kibbled diet and were assigned to four scFOS treatments (0, 1, 2, or 3 g/d) in a 4 x 4 Latin square design. Ileal nutrient digestibilities tended to increase (P < 0.15) with increasing concentrations of scFOS. On a DMI basis, fecal output tended to decrease linearly (P < 0.10) in response to increasing scFOS supplementation, whereas fecal score tended to exhibit a quadratic response (P = 0.12). In general, fecal concentrations of SCFA, BCFA, ammonia, phenols, and indoles were not altered by supplemental scFOS. Supplementation of scFOS increased fecal concentrations of total aerobes (P < 0.05) and decreased concentrations of Clostridium perfringens (P < 0.05). From these data, it seems that low levels of supplemental fructans have divergent effects on nutrient digestibility and fermentative endproducts, but do not adversely affect nutrient digestibility or fecal characteristics and may improve colonic microbial ecology in dogs.

Raw and rendered animal by-products as ingredients in dog diets.

Approximately 25 to 40% of the DM in premium dog diets is animal by-product. However, limited information is available regarding the composition and digestibility of these by-products, especially small intestinal digestibility. The effects of raw and rendered animal by-products incorporated into dog diets on nutrient digestion at the ileum and in the total tract were studied in this experiment. Diets fed contained various animal by-products including a rendered beef meat and bone meal (RMBM); fresh beef (FB); poultry by-product meal (PBPM); fresh poultry (FP); a plant-based control protein source, defatted soy flour (DS); and an animal-based control protein source, dehydrated whole egg (WE). The diets were extruded and kibbled. By-products varied widely in concentrations of OM, CP, amino acids, and fat. Nutrient intakes were numerically higher for FB than for all other treatments. All nutrient intakes were higher (P < .03) for the FB treatment than for the RMBM treatment. Digestibilities of DM, OM, CP, fat, and GE at the ileum were higher (P < .06) when dogs were fed diets containing FP than when fed diets containing PBPM. Amino acids were highly digestible at the ileum; however, digestibilities of all amino acids except cystine were higher (P < .04) for the diets incorporating FP vs PBPM. Total tract digestion was different among treatments for DM (P < .02), OM (P < .01), and GE (P < .02), and diets containing animal by-products were similar in total tract digestibility, greater than the DS control, and lower than the WE control. Rendering of poultry, but not beef, seemed to have a slight negative influence on small intestinal, but not total tract, digestibility by dogs.

Selected animal and plant protein sources affect nutrient digestibility and fecal characteristics of ileally cannulated dogs

The objective of this study was to compare ileal and total tract nutrient digestibilities and fecal characteristics of dogs fed selected animal and plant protein sources incorporated into grain‐based diets. Four crude protein sources ‐ soybean meal (SBM), poultry meal (PM), poultry by‐product meal (PBPM), and beef and bone meal (BBM) ‐ were fed to four ileal cannulated dogs in a 4 x 4 Latin square design. Intakes of dry matter, organic matter, crude protein, and fat by dogs were similar. Total dietary fiber (TDF) intake was highest for the SBM treatment compared to other treatments. Ileal digestibilities of DM, OM, CP, fat, and TDF were not affected by treatment. Total tract digestibility of DM was lower for the BBM and SBM diets, while OM digestibility was lower for the SBM treatment only. Total tract CP digestibility was similar for BBM, PBPM, and SBM treatments and was higher for the PM treatment. As‐is fecal excretion [g/d] was greater when dogs received the SBM treatment. Fecal output on a DM basis was higher for the SBM treatment compared to the other treatments. All diets were well utilized by the dogs as assessed by ileal and total tract digestibility data and fecal characteristics.

Apparent digestibility and glycaemic responses to an experimental induced viscosity dietary fibre incorporated into an enteral formula fed to dogs cannulated in the ileum.

The purpose of this study was to evaluate the apparent digestibility and postprandial glycaemic responses of ileal-cannulated dogs when fed an experimental induced viscosity dietary fibre (IVF) incorporated into a liquid enteral formula. Dietary treatments were: (1) control; (2) Glucerna; (3) Glytrol; (4) IVF; and (5) Jevity. Diets varied in concentrations of crude protein (CP), fat, starch and total dietary fibre (TDF). Dry matter and starch intakes by dogs fed the Glucerna and Glytrol treatments were lower (P<0.05) than for those consuming the other diets. However, daily intakes of CP and fat followed a reverse trend. Digestibility of nutrients at the ileum was high (>80%) for all dietary treatments. Mineral absorption proximal to the ileum and from the total tract was not significantly different among treatments. Mean incremental area under the serum glucose response curves for dogs fed Glytrol, Glucerna, and IVF treatments were lower (P<0.05) than the control treatment. Induced viscosity fibre appears to have no negative effects on nutrient digestion throughout the gastrointestinal tract. Its ability to moderate serum glucose concentrations would make it a potentially good choice for a diabetic liquid formula.