An experiment was conducted with the objective to verify the effect of different levels of available phosphorus (aP) and of calcium (Ca) in the diet on the performance, the quality of eggs and the nutritional status of the bone tissue of japanese quails during the initial laying phase. A total of 700 japanese quails, with 61 days of age, distributed in 70 experimental units with 10 birds each were used. A completely randomized experimental design was use, in a 5 × 2 factorial arrangement with five levels of aP (0.15; 0.25; 0.35; 0.45 e 0,55%) and two levels of Ca (2.5 e 3.2%), with seven replicates per treatments. The experimental diets were isoprotéicas (20.0% CP), isocalóricas (2.900 kcal ME/kg) and isoaminoacids. The levels of aP influenced by a quadratic form, the height and the average diameter of the eggs, the Ca egg shell content and percentage of Ca (2.5% Ca) and P (3.2% Ca) in the bones. There was a linear improvement for the commercial egg production and percentage of P in the bones (lower level of tested Ca), up to the level of 0.31% and of 0.51% P, respectively, in the diet. As aP levels increased in the diet, the conversion for dozen of eggs linearly decreased and the percentage and yolk weight reduced up to the levels of 0.40 and 0.25% of aP, respectively, in the diet. The shell weight, percentage and thickness, specific weight, shell Ca content and percentage of Ca in the bones were influenced by the Ca levels in the diet. There was no influence of the Ca and a aP levels on eggs production, ration consumption, egg mass, feed conversion per eggs mass, viability, final average weight of the birds and percentage and weight of albumen in the eggs. Dietary levels of 2.5 and 0.31% aP are enough to provide good productive performance and satisfactory maintenance of the quality of eggs and nutritional status of bone tissues of Japanese quails during the initial laying period.
Coturnix coturnix japonica; egg quality; nutritional status; productive performance
