The effect of adding two enzyme mixtures in diets for dogs formulated with wheat bran was evaluated.
Two foods with similar compositions were formulated: negative control (without wheat bran) and test diet (25% of wheat bran). The test diet was divided into four treatments: without enzyme (positive control), enzyme mixture 1 (ENZ1; added before extrusion Î²-glucanase, xylanase, cellulase, glucoamylase, phytase), enzyme mixture 2 (ENZ2; added before extrusion the ENZ1 more Î±-amylase) and enzyme mixture 2 added after the extrusion (ENZ2ex). ENZ1 and ENZ2 were used to evaluate the enzyme effect on extruder pre-conditioner (processing additive) and ENZ2ex to evaluate the effect of enzyme supplementation for the animal. Digestibility was measured through total collection of feces and urine.
The experiment followed a randomized block design with five diets and six dogs per diet, totaling 30 dogs. Reducing sugars showed an important reduction after extrusion, suggesting the formation of carbohydrate complexes. The apparent total tract digestibility of dry matter, organic matter, crude protein, acid-hydrolyzed fat and energy was higher in the negative control than in diets with wheat bran, without effects of enzyme additions. Wheat bran diets resulted in higher fecal production and concentration of short-chain fatty acids and reduced pH and ammonia concentration, with no effect of enzyme addition.
The enzyme addition did not result in improved digestibility of a diet high in non-starch polysaccharides; however, only apparent total tract digestibility was measured and nutrient fermentation in the large intestine may have interfered with the results obtained. Wheat bran modified fermentation product formation in the colon of dogs.
Source: F.C. Sa et al., 2013. Enzyme use in kibble diets formulated with wheat bran for dogs: effects on processing and digestibility. JAPAN online, May 2013. doi: 10.1111/jpn.12047