Effect of phytase in laying hen diets with different phosphorus sources - Casartelli, Elenice Maria; Junqueira, Otto Mack; Laurentiz, Antonio Carlos de; Filardi, Rosemeire da Silva; Lucas Junior, J; Araújo, Lúcio Francelino (Revista Brasileira de Ciência Avícola = Brazilian Journal of Poultry Science, 2005)