Intake of energy, protein, amino acids and minerals by dogs under energy restriction for body weight loss when fed with commercial weight loss diets.

This retrospective study evaluated energy and nutrient intake of dogs in a weight loss programme. Ninety-four obese dogs were divided into three groups: G5-15: from 5% to 15% body weight (BW) loss (n = 55); G155-25: from 15.1% to 25% BW loss (n = 29); and G > 25: more than 25.1% BW loss (n = 10). Five brands of kibble diets designed for weight loss were analysed for crude protein, amino acids, fat, dietary fibre, and minerals. The food metabolizable energy (ME) was estimated (NRC, 2006). Data were compared inside each group using the paired t test and between groups with analysis of variance and Tukey tests (p < 0.05). The BW loss (weeks in regimen) was: G5-15, 9.8% ± 2.7% (13.5 ± 5.7 weeks); G15-25, 17.5% ± 2.7% (22.6 ± 11.9 weeks); G > 25, 30.0% ± 2.1% (50.4 ± 17.4% weeks; p < 0.01). The mean weekly BW loss rate was similar between groups (0.8% ± 0.3%; p > 0.05) but was higher during the first (0.96.6% ± 0.5%) than in the second (0.64% ± 0.4%) half of the regimen (p < 0.01). At beginning ME intake for BW loss did not differ (251.6 ± 32.2 kJ/kg0.75 /day), but it was lower for G > 25 in the second half of the regimen (230.3 ± 44.3; p = 0.02). Considering the observed ME intake of each dog, depending on the commercial product, intake below recommended for maintenance was verified for crude protein in 1%-20% of the dogs, methionine in 4%-38% of dogs, methionine plus cystine in 4%-22% of dogs, tryptophan in 7%-93% of dogs, potassium in 2%-85% of dogs and magnesium in 1% up to 95% of dogs. Although the diets presented elevated nutrient concentrations per MJ, due to the reduced energy allowance, the estimated intake of several nutrients was lower than the recommendations, highlighting the importance of changing the formulation perspective, which must prioritize the actual nutrient intake per kg of BW during the energy deficit.

Effect of orange fibre on nutrient digestibility and fermentation products in faeces of cats fed kibble diets.

The aim of the present study was to compare orange fibre, beet pulp and inulin as fibre sources for cats. A control diet (CON) was formulated without inclusion of a fibre source. Further experimental diets were also based on diet CON but were supplemented with 1% orange fibre (diet 1%OF); 3% orange fibre (diet 3%OF); 3% beet pulp (diet 3%BP) or 1% inulin (diet 1%IN). Forty cats were used in a randomised block design (4 blocks of 10 cats, 2 animals per food in each block, totalling 8 animals per treatment). Each block lasted 20 d, with 10 d of adaptation, 10 d of faecal collection for digestibility as well as evaluation of pH-value and fermentation products. The digestibility of dry matter, organic matter, crude protein, ether extract, starch and gross energy did not vary between diets. In diet 1%OF, dietary fibre revealed a greater digestibility than in diet CON (p < 0.05). Faecal production was higher in cats fed diets 3%OF and 3%BP than in those fed diet 1%IN (p < 0.05). Faecal concentrations of acetate and total short-chain fatty acids were higher for cats fed diet 3%BP than for those fed diets 1%IN and CON (p < 0.05), while diets 1%OF and 3%OF showed intermediate results. Faecal propionate concentration was higher for cats fed diet 3%BP, intermediate for diets 1%OF, 3%OF and 1%IN and lower for animals fed diet CON (p < 0.05). Compared with diets CON and 1%IN, the faecal concentration of tyramine was higher for cats fed diet 3%OF (p < 0.05). Orange fibre was fermentable; up to 3% inclusion it did not interfere with the digestibility of nutrients, faecal score and faecal moisture content, and promoted the formation of short-chain fatty acids and tyramine by the intestinal microbiota, with possible effects on intestinal function.

Effects of the solubility of yeast cell wall preparations on their potential prebiotic properties in dogs.

Derivatives of yeast cell wall (YCW) have been studied for their potential prebiotic effects. Recently, new purified and soluble preparations have been developed in an attempt to increase their biological actions. Two YCW preparations, one conventional and another with higher solubility of the mannan oligosaccharide fraction, were evaluated on dogs. One food formulation was used, divided into the following treatments: CON-control, without yeast cell wall addition; YCW-addition of 0.3% of a conventional yeas cell wall extract; YCWs-addition of 0.3% of a yeast cell wall extract with high mannan oligosaccharide solubility. Twenty-four beagle dogs were used, eight per food, distributed on a block design. Blocks lasted 32 days, and TNF-a, IL-6, IL-10, ex vivo production of hydrogen peroxide and nitric oxide by peripheral neutrophils and monocytes, phagocytic index, and fecal IgA were evaluated at the beginning and end of each period. Additionally, nutrient digestibility, feces production and quality, and fermentation products were quantified. The results were evaluated by analysis of variance and compared using the Tukey test (P<0.05), using the basal immunological parameters as a covariate. The inclusion of YCWs reduced fat digestibility (P<0.05), increased the concentration of butyrate and putrescine, and reduced lactate in feces (P<0.05), showing that mannan oligosaccharide solubilization resulted in higher fermentation of this compound and altered the metabolism of the gut microbiota. Lower IL-6 on serum was verified for dogs fed the YCWs diet (P<0.05), suggesting a reduction in the inflammatory activity of dogs. Higher phagocytic index was verified for peripheral monocytes after the intake of the YCW food, suggesting better innate immunity. In conclusion, the solubilization of the mannooligosaccharide fraction alters its interaction with gut microbiota and biological actions in animals, although both yeast cell wall preparations exhibited prebiotic effects on dogs.