PSXI-5 - Digestibility and Acceptability of Foods Containing Increasing Content of Rice Protein Concentrate Fed to Adult Cats

Abstract: The use of rice protein concentrate (RPC) as a protein source in cat food is not common. Therefore, the purpose of this study was to determine the acceptability and digestibility of foods formulated to contain increasing content of RPC to support its inclusion in foods for adult (non-gestational, non-lactational) cats. Increasing RPC (0, 7, 14, and 28%) were formulated into test foods fed to 24 cats in a Latin Square design with 15-day periods and no washout between periods. Food intake and fecal scores were measured to determine acceptability of test foods. Food intake and fecal output were measured on days 11-15; food and fecal samples from day 15 of each period were analyzed for nutrient composition to calculate macronutrient digestibility of the test foods. Analysis of variance and orthogonal contrasts were utilized to assess the effect of RPC inclusion on food intake, fecal output, fecal scores, and macronutrient digestibility. As-fed, dry matter (DM), and gross energy intake increased with increasing RPC inclusion (P = 0.040, 0.017, and 0.040, respectively). Fecal output, both as-is and DM, was unaffected by RPC inclusion (P = 0.267 and 0.685, respectively); however, fecal scores increased linearly with increasing RPC inclusion (P < 0.001). Rice protein concentrate inclusion in test foods linearly increased digestibility of all macronutrients (P < 0.050) except for apparent fat digestibility, which was unaffected by RPC inclusion (P = 0.690). This study demonstrated that RPC can serve as a high-quality, acceptable protein source in foods fed to adult cats. Overall, the inclusion of RPC was well accepted, improved fecal characteristics, and increased apparent and true macronutrient digestibility compared to control.