No abstract

No abstract

The objective was to evaluate the coefficients of total tract apparent digestibility (CTTAD) and metabolisable energy (ME) of raw soybeans (RSB) in extruded diets for dogs by three methods (difference, regression and substitution). We also evaluated the urease and trypsin inhibitor (TI) activity, CTTAD, ME and faecal characteristics of adult dogs fed diets containing increasing RSB levels. Six dogs, distributed in a 6 Â 6 Latin square design, were fed extruded diets containing 0, 60, 120, 180, 240 or 300 g of RSB/kg. Urease and TI were reduced in all diets after extrusion (p < .01), but TI was not completely inactivated. The inclusion of RSB linearly reduced (p < .01) the digestibility of dry matter (DM), organic matter and crude protein (CP) and linearly increased (p < .05) the digestibility of fat and gross energy and the ME of diets. The CTTAD of DM, CP and fat, and ME of RSB, predicted by the substitution method were: 0.767, 0.758, 0.960 and 20.7 MJ/ kg, respectively. The dietary inclusion of RSB reduced faecal DM content and promoted a quadratic increase (p < .01) of pH and ammonia. Increasing RSB in diet reduced CTTAD estimate errors (p < .05). When 300 g of RSB were added per kg of diet, CTTAD of RSB estimated by the three methods did not differ (p>.05). The three methods can be used to determine RSB digestibility. Diet extrusion may not be able to completely deactivate the protease inhibitors present in the RSB. HIGHLIGHTS Extrusion may not be able to deactivate protease inhibitors of raw soybeans. Raw soybeans reduce nutrient digestibility of extruded diets in dogs. The substitution method is recommended to evaluate digestibility of raw soybeans.

This study aimed at evaluating the coefficients of total tract apparent digestibility (CTTAD) of nutrients, metabolisable energy (ME), diet palatability, faecal fermentative products and microbiota of dogs fed yeasts from different fermentation media and its fractions. Four diets were evaluated: control, without yeast (CO); diet with 10 g/kg brewer's yeast (BY); diet with 10 g/kg brewer's yeast + corn yeast (BCY); and diet with 10 g/kg BCY + cell wall fractions (BCYF). Twelve adult dogs were distributed in a randomized block design (periods). Each of the four diets was fed to a group of three dogs per period of 20 days, totalling two periods and six repetitions per treatment. Sixteen adult dogs were used for the palatability test, which compared the CO diet versus each one of the yeast diets. Data with normal distribution were subjected to analysis of variance (p < 0.05). Means were compared by orthogonal contrasts (p < 0.05): (A) CO diet versus BY, BCY and BCYF diets; (B) BY diet versus BCY and BCYF diets; (C) BCY diet versus BCYF diet. There was no difference in the CTTAD and ME of the diets (p > 0.05). Yeast diets reduced faecal odour and indole peak area (p < 0.05). Faecal short-chain fatty acids concentration was greater in dogs fed yeast diets compared to those fed the CO (p < 0.05). Yeast diets showed a higher intake ratio compared to the CO (p < 0.05). The BCY and BCYF diets resulted in a greater abundance of Bacteroides, Faecalibacterium, Coprococcus, and Phascolarctobacterium in relation to the CO (p < 0.05). Our results suggest that dietary yeast supplementation results in beneficial changes in intestinal functionality indicators, mainly with the combination of yeasts from brewers and corn fermentation media. In addition, yeast supplementation improves diet palatability without compromising nutrient digestibility.

The objective was to evaluate kibble characteristics, coefficients of total tract apparent digestibility (CTTAD) of nutrients, metabolisable energy (ME), palatability, and faecal characteristics of diets containing potato starch (PS) fed to adult dogs and puppies. Four diets containing 0, 100, 200, or 300 g/kg PS, at the expense of corn, were evaluated in three experiments. Experiment 1 evaluated the physical characteristics of the diets. Experiment 2 evaluated diet digestibility and faecal characteristics in eight adult dogs (7 years old) and eight puppies (6 months old) according to a double 4 Â 4 Latin square design. Experiment 3 evaluated palatability (0 vs. 100 g/kg of PS and 0 vs. 300 g/kg of PS diets) using 16 puppies. Diets with the highest PS level presented the largest kibbles expansion ratio, greater hardness and number of pores while the density was decreased (p < .001). The inclusion of PS increased (p < .05) CTTAD of dry matter (DM) and gross energy, and ME of diets and faecal DM, for adult dogs and puppies, and CTTAD of crude protein and total starch in puppies (p < .05). Potato starch reduced ammonia levels in the faeces of puppies (p < .001). Faecal pH and score were not influenced by dietary PS inclusion either in adult dogs or puppies (p > .05). Puppies preferred diets (p < .05) containing higher PS levels. The addition of PS in the diets produces kibbles with a high expansion index and low density. Potato starch is a good starch source for adult dogs, and particularly for puppies, as it improves the digestibility of dietary nutrients and increases faecal DM, in addition of being more palatable than corn. HIGHLIGHTSPotato starch increases expansion and reduces density of kibbles. Potato starch presents higher digestibility and metabolizable energy than corn. Potato starch improves diet palatability.