PSIX-10 Influence of Graded Levels of Microbially Enhanced Protein on Nutrient Digestibility of Extruded Cat Foods

Abstract

Abstract Pet food ingredients that bring extra nutrition and health benefits are much better accepted than being simply an economic choice by the manufacturer. Microbially enhanced protein (MEP) from soybeans is a fermented ingredient that is believed to promote nutrient utilization. The objective of this study was to determine the effect of increasing levels of MEP on nutrient digestibility of extruded cat food. Four extruded dietary treatments differing by level of MEP in exchange for soybean meal (15%; SBM) at 5, 10 and 15% (5MEP, 10MEP and 15MEP, respectively) were randomly assigned to 12 individually housed adult domestic shorthair cats (6 castrated males and 6 spayed females) of similar age (0.9 ± 0.23 months) and body weight (4.35 ± 0.87). The study was designed as a 4 × 4 replicated Latin square with 9-day adaptation followed by 5-day total fecal collection for each period. Data were analyzed using a mixed model through SAS (version 9.4, SAS Institute, Inc., Cary, NC) with treatment as a fixed effect and square (i.e., replicate), period, and cat(square) as random effects. Treatment means were separated by Tukey’s test. The 15MEP increased fecal moisture content (P<0.05) while 5MEP and 10MEP made no difference compared with SBM. No differences were observed for food intake, fecal dry matter output, fecal score, fecal pH or apparent total tract digestibility of dry matter, organic matter, crude protein or gross energy for MEPs compared with SBM. However, crude fat digestibility of cats fed 5MEP was lower (P<0.05) than cats fed with10MEP and 15MEP but not different from cats fed with SBM. These results suggest that MEP did not have adverse effects on nutrient digestibility when added to extruded diets at up to 15% in healthy adult cats.