Nonphytate concentration of phosphorus in the diet can be reduced below 1.5 g/kg at the exact nutrient composition and nutrient stability of mixed feed. Commercial mixed feed for laying hens lack the necessary nutrient stability. Therefore, we recommend nonphytate phosphorus content in the mixed feed in the range from 1.8 to 2.1 g/kg excluding the effect of phytase. We recommend adding phytase at a dose of 150 to 300 FTU/kg to the basic nonphytate concentration of phosphorus in the mixed feed in the amount of 1.8 to 2.1 g/kg.