Evaluation of low-oligosaccharide and low-oligosaccharide low-phytate whole soya beans in canine foods

Abstract

Eight mature dogs (19.7 ± 0.1 kg) were used in a 4 × 4 Latin square experiment to evaluate low-oligosaccharide whole soya beans (LO) and low-oligosaccharide low-phytate whole soya beans (LOP) as protein sources in complete foods fed to dogs. All foods were isonitrogenous and contained either LO, LOP, conventional soya bean meal (SBM) or low-ash poultry meal (PM) as the protein source. Daily DMI averaged 360 ± 28 g/d. The two whole soya bean (WSB) foods resulted in the highest fecal outputs averaging 47.9 g DM/d. The coefficient of ileal apparent (CIAD) DM digestibility was highest for PM (0.862) and averaged 0.784 for all soy-based foods. The coefficient for large intestinal apparent (CLIAD) DM digestibility was similar for all foods (0.381; P = 0.681). The coefficient of total tract apparent (CTTAD) DM digestibility was highest for PM (0.913; P = 0.003) and lowest for the WSB containing foods (0.856; P = 0.012). Fecal N excretion was lowest for PM foods (1.5 g N/d; P = 0.031) when compared to all soy-based foods. No difference in N retention was observed amongst all foods (1.0; P = 0.949). The CIAD for N did not differ among foods (0.745; P = 0.497) whereas, CLIAD for N was highest for PM (0.486; P = 0.003). The N CTTAD was highest for the PM food (0.864; P = 0.017) and lowest for WSB foods (0.821; P = 0.049). Phenylalanine, aspartate, cysteine, glutamate, serine and tyrosine CIAD were lowest for PM. All other digestibilities were not affected by treatment. No differences in nonessential AA CIAD were observed when comparing soya-based foods. Dogs consuming SBM had higher isoleucine, phenylalanine and tryptophan CIAD when compared to WSB foods. These data indicate that LO, LOP and SBM can serve as sources of protein for canine foods. However, the WSB foods had increased fecal output, lower digestibility and lower fecal quality when compared to PM and SBM. Phytate levels up to 1.5 g/kg in dry extruded foods exhibited no negative effects on digestibility.