Common protein sources used in the manufacturing of diets for dogs are derived from by-products, which may have reduced digestibility depending on the source. This study evaluated the effect of the addition of a protease, the papain enzyme, as a supplement to extruded diets on palatability, nutrient digestibility, and fecal production and quality of dogs. A diet was formulated with poultry by-product meal, meat and bone meal, and feather meal as protein sources. This formula was divided into three isonutrient diets: one negative control (NC), without enzymes; treatment one (EZ1) with addition of 855.000 UI of papain per kilogram of diet, and treatment two (EZ2) with addition of 2.280.000 UI of papain per kilogram of diet, both added before extrusion. The experiment followed a randomized block design, with two blocks of nine animals (three animals per treatment in each block), 18 dogs in total, and six replicates per treatment. Data were submitted to analysis of variance and the means of three treatments were compared by polynomial contrasts (P 0.05). The fecal score was reduced with increased addition of enzyme (P < 0.05).

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Processo FAPESP: 2011/17502-3