Phosphorus utilization in pigs with phytase

Digestibility trials were conducted with growing-finishing pigs from three genetic lines to determine phosphorus (P) excretion in manure and P absorption in the pig fed typical corn-soy diets but containing 26 to 29% lower P levels with added phytase (Natuphos, BASF, Inc.) at 500 or 1000 U per kg. A standard P diet and a low P diet with phytase and low protein balanced with four synthetic amino acids was included. Addition of 1000 U of phytase to the low P diets increased P digestibility in 65 kg pigs from 7.5 to 15.2 percentage U and reduced P content in feces by 26 to 41% compared to the pigs fed the control P diet without phytase.