RESUMO
Feed additives, such as prebiotics and essential oils, are used in pet foods and can affect digestibility, palatability, and intestinal functionality of dogs. The combined effects of yeast cell wall and oregano essential oil on apparent total tract digestibility (ATTD) and palatability of diet, intestinal fermentation products, and fecal microbiota in dogs were analyzed. Eighteen adult dogs were fed for 20 days with three dry extruded diets for adult dogs: control (without the additive), a diet containing 1.5 kg/ton of yeast cell wall and oregano essential oil (1.5YCO), and a diet containing 3.0 kg/ton of yeast cell wall and oregano essential oil (3.0YCO). The inclusion of both levels of YCO reduced the intake ratio. The addition of 3.0YCO reduced the ATTD of dry matter, compared to the control group (p < 0.05). There were greater putrescine and cadaverine concentrations and lower histamine and ammonia (p < 0.05) in the feces of dogs fed 3.0YCO. In addition, fecal odor of dogs fed YCO was less fetid than the control group (p < 0.05). There was greater fecal bacterial diversity in dogs fed with both dietary concentrations of YCO evaluated (p < 0.05). Dogs fed 1.5YCO and 3.0YCO showed higher relative abundance of Blautia and Faecalibacterium and lower abundance of Streptococcus (p < 0.05) in the feces, in comparison to the control group. Given the modulation of microorganisms considered beneficial and the lower fecal concentrations of histamine, phenols, and ammonia, the YCO blend resulted in indicators of improvement of intestinal functionality in dogs.
RESUMO
This study aimed to evaluate the effects of high-protein dried distillers grains (HPDDG) on palatability and metabolizable energy (ME) of the diet, apparent total tract digestibility (ATTD) of nutrients and energy, intestinal fermentation products, and fecal microbiota in dogs. Four diets containing 0, 70, 140, and 210 g/kg of HPDDG were manufactured. To evaluate the ME and the ATTD of macronutrients of HPDDG itself, an additional test diet was manufactured containing 70% of the control diet formula (0 g/kg) and 300 g/kg of HPDDG. Fifteen adult Beagle dogs were distributed in a randomized block design, with two periods of 15 d each (n = 6). The HPDDG digestibility was obtained using the Matterson substitution method. For the palatability test, 16 adult dogs were used, comparing the diets: 0 vs. 70 g/kg of HPDDG and 0 vs. 210 g/kg of HPDDG. The ATTD of HPDDG were: dry matter = 85.5%, crude protein = 91.2%, and acid-hydrolyzed ether extract = 84.6% and the ME content was 5,041.8 kcal/kg. The ATTD of macronutrients and ME of the diets and the fecal dry matter, score, pH, and ammonia of the dogs did not differ among treatments (P > 0.05). There was a linear increase in the fecal concentrations of valeric acid with the inclusion of HPDDG in the diet (P < 0.05). Streptococcus and Megamonas genera reduced linearly (P < 0.05), and Blautia, Lachnospira, Clostridiales, and Prevotella genera showed a quadratic response to the inclusion of HPDDG in the diet (P < 0.05). Alpha-diversity results showed an increase (P < 0.05) in the number of operational taxonomic units and Shannon index and a trend (P = 0.065) for a linear increase in the Chao-1 index with the dietary inclusion of HPDDG. Dogs preferred the 210 g/kg diet over the 0 g/kg HPDDG diet (P < 0.05). These results demonstrate that the HPDDG evaluated does not affect the utilization of nutrients in the diet, but it may modulate the fecal microbiome of dogs. In addition, HPDDG may contribute to diet palatability for dogs.
Considering the constant search for novel ingredients in animal nutrition and the increasing use of corn to produce ethanol, dried distillers grains with (DDGS) or without (DDG) solubles can potentially be used in dog food. Previous studies show that DDGS and DDG can contribute mainly with protein and fiber to the diets and that their fibrous fraction can potentially be fermented by the gut microbiota. However, DDGS and DDG may present variable digestibility in dogs. Besides, we did not find studies evaluating the nutritional effects of high-protein DDG (HPDDG) in dogs. This study evaluated the effects of HPDDG on diet digestibility and palatability and on variables related to the intestinal functionality of adult dogs. Our results demonstrated that HPDDG can be used in extruded diets for dogs due to its high digestibility and palatability. Besides, the HPDDG evaluated may result in a modulation of the gut microbiota, favoring bacteria considered beneficial for gut health.