Characterizing Fecal and Manure Phosphorus from Pigs Fed Phytase Supplemented Diets

We conducted this study to characterize phosphorus (P) forms in feces and manure from pigs fed phytasesupplemented diets and to determine if higher phytase levels can result in greater reduction in manure P withoutincreased P solubility. Twenty-eight growing pigs were fed diets containing varying levels of supplemental Pand phytase. Phosphorus concentrations in feces, urine and manure were determined and fecal and manure Pwere fractionated. Phytase addition reduced P concentration in feces and manure but increased urine Pconcentration. The greatest significant reduction in fecal and manure P was in pigs fed diet containing 2000 Uphytase kg-1 without supplemental P, with 33% reduction in manure P. Inorganic P constituted more than 85% offecal and manure P and the percentage decreased with phytase addition. Our study showed that higher phytaselevels up to 2000 U phytase kg-1 could offer additional advantage of reducing manure P concentration andsolubility