Complete Enzymic Dephosphorylation of Corn-Soybean Meal Feed under Simulated Intestinal Conditions of the Turkey

A crude laboratory phytase preparation, a commercial phytase, and a commercial experimental phytase were used in vitro to study the extent of corn-soybean feed (P sub(tot): 4.83 plus or minus 0.06 g/kg) dephosphorylation under simulated intestinal conditions of the turkey. The phytases had different specific activities; varied in side activities of acid protease, acid phosphatase, and pectinase; and revealed different abilities for feed dephosphorylation. Acid phosphatase was shown to be a key activity in feed dephosphorylation, while fungal acid protease enhanced dephosphorylation by stimulating gastric digestion. An "enzymic cocktail" that completely dephosphorylated phytates present in corn-soybean feed also contained pectinase and citric acid. Complete dephosphorylation was accompanied by 12-29% increase in dialyzable protein, and 45-81% increase in the concentration of reducing sugars liberated from feed. The potential use of the "cocktail" as a feed additive for monogastric animal may result in improved digestibility of phytate phosphorus, protein, and carbohydrates.