PSIII-20 Use of legumes and yeast as main protein sources in extruded canine diets

Plant-based protein sources have gained popularity as consumer demand for grain-free and novel protein sources increase. However, minimal information is available about the effects on digestibility, gastrointestinal tolerance, and fermentative end-products of novel plant-based proteins in dogs. Therefore, the objective of this study was to evaluate legumes and yeast as protein sources in extruded canine diets. Five diets were formulated to be isocaloric and isonitrogenous with either garbanzo beans (GB), green lentils (GL), peanut flour (PF), dried yeast (DY), or poultry byproduct meal (CON) as the primary protein source. Ten, adult, female beagles (mean age: 5.0 ± 1.2 years, mean BW: 11.9 ± 1.3 kg) were used in a replicated 5x5 Latin square design. Each 14 d period consisted of a 10 d diet adaptation followed by a 4 d total fecal and urine collection. At the end of each period, 5 mL of blood was collected and analyzed for a complete blood count and serum chemistry. Serum metabolites were within normal ranges and all dogs remained healthy throughout the study. Fecal scores, evaluated on a 5-point scale, were considered ideal and did not differ among treatments. Apparent total tract digestibility (ATTD) of dry matter and organic matter was highest (P < 0.05) for CON (86.3% and 91.2%, respectively) and PF (85.6% and 90.3%, respectively) and lowest (P < 0.05) in dogs fed the DY diet (80.1% and 84.3%, respectively). GL had the lowest (P < 0.05) crude protein ATTD (81.5%) with no differences among other treatments (84.6% average). Dogs fed CON, PF, and GB diets had the highest (P < 0.05) acid hydrolyzed fat ATTD, with an average of about 94%. In conclusion, novel plant-based protein sources and yeast are comparable to traditional poultry byproduct meal diet and are appropriate protein sources for canine diets.