Dietetic combination of mannan-oligosaccharides and fructooligosaccharides modifies nitrogen metabolism in dogs

Abstract

The goals of this study were to evaluate the effects of a mannan-oligosaccharide (MOS) and a frutoligosaccharide (FOS) mixture in a 1:1 ratio added to a commercial diet for dogs before the extrusion process on the coefficient of total tract apparent digestibility (CTTAD) of the diets and on the metabolizable energy (ME), nitrogen metabolism (postprandial blood urea curve, organic nitrogen balance, fecal concentration of ammonia and excretion of urinary urea) and fecal fermentation parameters (fecal pH and concentrations of short chain fatty acids). Eighteen adult Beagle dogs were used and randomly distributed into two treatments, being a control diet plus one diet in which the mixture of prebiotics was added before the extrusion of the ration. There was no difference in digestibility, metabolizable energy, fecal ammonia content and short-chain fatty acids (acetic, propionic and butyric) between the control diet and the one with the addition of prebiotics. However, the dogs supplemented with prebiotics before extrusion, had a lower fecal pH (p < 0,05) compared to those in the control diet and a reduction in the post prandial blood urea concentration (p < 0,01) was also observed in the animals receiving prebiotics, observed by the areas below the curve of urea and its increment. The possible mechanism involved in the effect of prebiotics on the reduction in the concentrations of blood urea is the reduction in the formation and intestinal absorption of ammonia, favored by the reduction of intestinal pH. These findings can be considered in the use of prebiotics in clinical nutrition.