There hundred and eighty four (384) 54-wk-old hens of a commercial Leghorn strain (Hi line W- 36) were used in a factorial complete random design experiment with four treatments and five replications for a period of seven weeks . Treatments included diets with different available levels of Ca and P in the morning (0500 to 1300 h) and in the afternoon and evening (1300 to 2100 h). Treatment 1 was a control standard diet with 0.25% P and 3.5% Ca levels which were fed in the morning and in the afternoon, equally. Treatment 2 had a lower calcium content (0.5%) in the morning and higher calcium content (6.5 %) in the afternoon and evening, while treatment 3 had a higher P level (0.4 %) in morning and lower P content (0.1 %) in afternoon and evening. In treatment 4, hens received 0.5% Ca and 0.4% vailable P in the morning, but 6.5% Ca and 0.1% P in the afternoon and evening. Feed intake, egg production (% hen/ days) and egg mass (g hen/ days) were recorded daily. All the eggs produced during three consecutive days (from 1500 h of the first day to 1500 h of the third day) on a bi-weekly period were saved for the measurement of egg weight. 25% of these eggs were used for the measurement of egg components (white, yolk and shell weight), shell thickness, and Haugh unit. In the morning of the last day of experiment one hen from each replicate was illed and the left tibia was saved for ash determination. Data were analyzed for production performance and egg quality in a factorial complete random design by JMP V 4.0.4. This experiment clearly showed that the use of diets with different concentrations of Ca and P in the morning and afternoon/evening, could improve the performance of production without affecting feed intake or egg quality, and hen health during the lat laying period.

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