At low levels of dietary calcium and phosphorus (2.8 and 0.36%, respectively), the degree of phytate conversion raised by adding phytase B to feeds that had already been supplemented with 3- or 6-phytase A, modulated production parameters, and egg shell quality of Hy Line Brown laying hens fed maize-soyabean meal from week 40 to 54. Feed consumption, laying rate, mean egg weight and shell breaking strength depended on the type of phytase A added to feeds only at a low phytate conversion degree. Egg production and feed per egg conversion ratio did not depend on the dietary supplements studied.