What are phytase-supplemented diets?

Pigs can only digest about one third of organic phosphorus present in feed grains and oilseed meals. Therefore, up to two thirds of the phosphorus from organic sources is excreted in the manure. Since so much of the organic phosphorus is unavailable, extra inorganic phosphorus (which is more digestible) must be included, bringing the total amount of phosphorus in feed well above the needs of the pig. One of the best ways to reduce phosphorus excretion is to supplement the diet with phytase, an enzyme not naturally present in mono-gastric animals. The addition of phytase makes organic phosphorus more digestible and limits the amount of inorganic phosphorus that must be added to the diet. Studies have shown that 20% or more, with the use of dietary phytase, can reduce phosphorus excretion.