ABSTRACT - This experiment was carried out to determine the endogenous fecal losses of P and the effect of phytase on the biological availability of P in the diets and in the whole rice meal (WRM) for growing swines, by means of the isotopic dilution technique. The barrows were allotted to a complete randomized experimental design, with four treatments and three replicates. The treatments consisted on two diets without WRM (with or without 1250 FTU [Unit of Phytase Activity]/kg diet), with 0.34% total P, and other two diets with WRM (with or without 1250 FTU/kg of diet), with 0.56% total P. An the 11th day, each animal was intravenously injected with 7.4 MBq 32P. The endogenous fecal losses of P were not affected by the action of phytase. The phytase addition reduced the total P excreted in the feces and improved the absorption and the biological availability of P of diets with whole rice meal.
bioavailability; whole rice meal; phytase; phosphorus; radiophosphorus; swine
