Phytate is an anionic compound that is known for its antinutritional effects. The most researched phytate is phaytate phosphorus, which is largely unavailable to nonruminant animals. Researchers have shown that phytate negatively affects amino acid availability in feedstuffs, decreases the activity of digestive enzymes to bind to dietary protein and amino acids and to form calcium-phosphate-phytate complexes with carbohydrates. It’s also been suggested that calcium-phytate complexes with fatty acids in the gut lumen forms insoluble metallic soaps, thus lowering fat digestibility. Dietary phytase is widely used in swine feeding programs to reduce phosphorus excretion in the manure by improving the dietary phytate phosphorus bioavailability to the pig. Research results have been inconsistent as to the effect of phytase on improving protein, amino acid, dry matter and nitrogen digestibility. The mineral concentration of diets fed to nonruminants also affects nutrient availability. It’s been reported that the ileal digestibility of essential amino acids and nitrogen were increased when dietary non-phytate phosphorus concentration was decreased in diets for poults and swine. Swine researchers S.L. Johnston, S.B. Williams, L.L. Southern, T.D. Bidner, L.D. Bunting, J.O. Matthews and B.M. Olcott at Louisiana State University Agricultural Center conducted two experiments to determine whether the reduction of dietary calcium and phosphorus, the addition of phytase or the combination of these two treatments (for a total of four treatments) would increase nutrient digestibility and utilization in corn-soybean meal diets for pigs. The data from these experiments suggest that the phytase addition of 500 phytase units per kilogram of diet, along with a 0.1% reduction in dietary calcium and phosphorus, increases amino acid and energy digestibility approximately 4% (varies depending on the amino acid and energy criteria measured) in corn-soybean meal diets for grow-finish pigs.