Phytase improved digestible protein, phosphorous, and energy contents in camelina expellers fed to growing pigs

Abstract

An experiment was conducted to determine the effects of supplemental phytase on apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of nutrients and energy in camelina expellers (CE) fed to growing pigs. The diets were a corn–soybean meal–based basal diet formulated to meet NRC nutrient requirements for growing pigs, the basal diet with energy-, AA-, and P-yielding ingredients replaced by 20% of CE without or with 500 FTU/kg of Buttiauxella spp. phytase. All diets contained TiO2 (0.4%) as an indigestible marker, and component digestibility in CE was determined by the difference method. A total of 9 ileal cannulated barrows (33.3 kg) were fed the diets in a 2-period crossover design. Each period lasted 9 d: 5 d for acclimation to the diets, 2 d for fecal collection, and 2 d for ileal digesta collection. Camelina expellers fed with phytase had greater AID of CP (66% vs. 56%) due to greater (P < 0.05) AID of Arg, Cys, Pro, Ser, and Tyr relative to CE fed without phytase. The AID of GE (55% vs. 47%) and P (68% vs. 38%) was great (P < 0.01) in CE fed with phytase compared to CE fed without phytase. Phytase improved (P < 0.05) ATTD of GE, P, and ADF in CE. Specifically, the DE and P contents in CE fed with phytase were, respectively, greater by 447 kcal/kg DM and 3.0 g/kg DM, which translated to 17% and 107% improvement on energy and P, respectively, relative to CE fed without phytase. The addition of phytase to a diet containing CE increased digestibility of nutrients and energy presumably due to increased utilization of nutrients bound to phytate.