PSIII-4 Nutritional evaluation of yeast biomass from candida utilis as a protein source in cat diets

Yeast products have found much favor within companion animal nutrition. A recently developed proprietary process has introduced an enhanced yeast biomass from Candida utilis (merchandised as SylPro®) into the animal food marketplace. Candida utilis has been shown to be a valuable protein in canine, swine and aquaculture diets; however, no previous research has evaluated its use in feline diets. Therefore, the current objective was to determine the nutrient digestibility of diets containing SylPro® yeast biomass (SYL) as the primary protein source relative to soybean meal (SOY), pea protein concentrate (PEA), and chicken meal (CKN) fed to cats. Apparent total tract digestibility (ATTD) of diets were estimated using Titanium dioxide as an indigestible marker. The DM ATTD for SYL was lower (P < 0.0001) than CKN (86.39 vs. 87.43%, respectively) but similar to both SOY (85.66%) and PEA (86.54%). The OM ATTD of SYL, SOY, and PEA were not different (P < 0.0001) and were each lower than CKN (average of 89.60 vs. 91.16%, respectively). The CP ATTD for SYL (89.9%) was not different from the other three treatments (P = 0.0200). Crude fat ATTD of SYL was lower (92.52%; P < 0.0001) than all treatments with PEA being greatest (94.82%) and CKN and SOY intermediate (average of 93.84%). The SYL and CKN had higher TDF ATTD (average of 66.20%; P < 0.0001) relative to PEA and SOY (average of 49.79%). The GE ATTD of SYL was lower than CKN (90.18 vs. 90.97%, respectively; P = 0.0154) but similar to both SOY (90.18%) and PEA (90.30%). In conclusion, all diets were highly digestible but CKN preformed the best. The SYL diet was similar to CKN for ATTD of CP and TDF. The SYL diet was also similar to both SOY and PEA for ATTD of DM, OM, CP and GE.