Dried distillers' grains, coproducts from the ethanol industry, may provide sustainable ingredients for pet food. Due to new post-fermentation separation techniques, corn-fermented protein (CFP) is higher in protein and lower in fiber compared with traditional dried distillers' grains, increasing its appeal for inclusion into pet food. Therefore, the objectives of this study were to determine the effects of increasing levels of CFP on stool quality, apparent total tract digestibility (ATTD), and palatability in adult cats. Four extruded diets were fed to 11 adult cats in an incomplete 4 × 4 replicated Latin square design. The control diet contained 15% soybean meal (0C) and CFP was exchanged for soybean meal at either 5%, 10%, or 15% (5C, 10C, 15C). Cats were fed each dietary treatment for 9-d adaption followed by 5-d total fecal collection. Feces were scored on a 1 to 5 scale, with 1 representing liquid diarrhea and 5 representing hard pellet-like (Carciofi et al., 2008). A fecal score of 3.5 to 4 was considered ideal. Titanium dioxide was added to all diets (0.4%) as a marker to estimate digestibility. Data were analyzed using a mixed model in SAS (version 9.4, SAS Institute, Inc., Cary, NC) with treatment as a fixed effect and cat and period as random effects. Fecal dry matter percent and dry fecal output were greater (P < 0.05) at elevated levels of CFP. Stool scores were maintained (P > 0.05) throughout treatments (average; 4). Dry matter, organic matter, crude protein, and gross energy ATTD decreased when cats were fed 15C. There was no difference in ATTD of fat or total dietary fiber among treatments. For palatability assessment, cats preferred 5C over 0C but had no preference with increased CFP inclusion. These results suggest that CFP is comparable to SBM, but there may be a maximum inclusion level of 10% when fed to cats.
Keywords: corn-fermented protein; feline; nutrient digestibility; palatability.
Sustainable ingredients are of increasing demand within the pet food industry. Corn-fermented protein (CFP) could provide a sustainable protein source for pet food. CFP is a coproduct from ethanol production, which is produced using post-fermentation separation technology to create a high-protein, low-fiber ingredient. In this work, 11 healthy cats were fed diets containing 0%, 5%, 10%, and 15% CFP in exchange for soybean meal. Cats were fed each dietary treatment for 14 d with a 9-d adaptation phase followed by a 5-d total fecal collection. Stool quality and diet digestibility were analyzed. Total fecal output of cats increased, and diet digestibility decreased with the 15% CFP inclusion. These results are likely due to the fiber component of CFP indicating a maximum inclusion level at 10% when fed to cats. In addition, palatability of diets was evaluated at a commercial kennel and proved to be acceptable at all CFP inclusion levels when fed to cats. Further research is needed to evaluate the possible impact of CFP on animal health when included in pet food.
© The Author(s) 2022. Published by Oxford University Press on behalf of the American Society of Animal Science.