Phosphorus Fractions Within Diet

The total phosphorus in the diet is composed of fractions with variable bioavailability. The addition of phytase creates an additional pool of available phosophorus from phytic acid, increasing the total pool of NPP available to the animal. Note that the diet supplemented with phytase is formulated to 0.46% total P, but it still delivers 0.35% AvP. This is because the phytase allowed 0.1% of previously unavailable phytic acid P to be released. This is the phytase equivalent phosphorus highlighted in the right-hand bar.