The intestinal and total tract digestibilities of phosphorus (P) and phytate P were determined in digestibility trials with laying hens and broiler breeders. In both digestibility trials, the total tract digestibility of phytate P was higher than the intestinal digestibility (33 and 35 % vs 20 and 18 %). In contrast, in both trials the total tract retention of P was lower than the intestinal retention (22 and 19 % vs 52 and 42 %). The average specific phytase activities in the crop, stomach, small intestinal contents, mucosa and caecal contents were 10.2, 9.2, 14.6, 11.5 and 135 μmol.h-1.g-1, respectively.