Comparison of micronized whole soybeans to common protein sources in dry dog and cat diets

The current investigation compared coefficients of total tract apparent digestibility (CTTAD), postprandial blood urea response and faecal characteristics for three isonutrient foods formulated with micronized whole soybeans (μSB), soybean meal (SBM) or poultry by-product meal (PPM) in dog diets and digestibility, palatability and faecal characteristics for two isonutrient foods employing either μSB or maize gluten meal (CGM) in cats diets. These protein sources represented 0.40 and 0.60 of total dietary protein in cat and dogs diets, respectively. In dogs CTTAD showed that μSB resulted in greater dry matter and fat digestibility than the PPM diet (P<0.05), and greater fat digestibility than the SBM (P<0.05) diet. Digestibility of fat was higher in the μSB diet fed to cats than in CGM diet (P<0.05). Faecal quality and production for both species was similar among all diets, with the exception of faecal dry matter that was greater (P<0.05) in dogs fed the PPM diet. Greater palatability, demonstrated as increased consumption (P<0.01), was verified for the μSB diet fed to cats. Mean incremental serum urea concentration and its incremental area under the curve were not different among treatments fed to dogs. It was concluded that micronized whole soybeans in combination with other protein sources containing complementary amino acids are a source of highly available, quality-consistent protein raw materials for both dog and cat diets.