Influência dos níveis de cálcio e fósforo na dieta de matrizes de codornas japonesas, no desempenho produtivo e no desenvolvimento ósseo embrionário da progênie

Abstract

The effects of calcium (Ca) and phosphorus (P) in the diet of Japanese quail hens were evaluated on performance and quality of eggs. The experimental design was completely randomized in a factorial arrangement of 4x2, composed of four levels of Ca (2.0, 2.5, 3.0, 3.5%) and two levels of P (0.25; 0.35% ) with 8 experimental units of 6 females and 2 males. For the productive performance and egg quality variables of hen there was no significant effect (P <0.05), except for Haugh unit (HU). For optical mineral density (mm / Al) was quadratic effect for tibialtarsus and linear effect for the femur in the calcium levels. During the period in which the hen received different levels of Ca and P were evaluated incubation parameters and embryonic bone development. In the incubation, the percentage of Ca of the embryo, shell and yolk were assessed at 7, 9, 11 and 15 day old embryo and described the areas of femur and tibialtarsus ossification. The percentage of calcium decreased in the shell and yolk and raised in embryo, showing the calcium transfer from these two components to the developing organism. The development of the femur and the tibialtarsus showed that the bones have distinctive pattern of growth and calcium deposition in the diaphysis. The progeny performance was evaluated in 4 replicates of 22 birds. The eggs fertility in incubation had quadratic effect on calcium levels. For the production parameters, there was a quadratic effect of calcium within the level of 0.25% of phosphorus to the weight at 7 and 21 days old chicks. The feed conversion and feed intake had an effect in the period of 1 to14 days of age within the phosphorus levels provided in the diet. For phase 1 to 35 days was observed effect of calcium on the progeny weight gain. Regarding bone parameters analyzed there was effect (P <0.05) for breaking strength (kgf) of the tibialtarsus and percentage of bone ash at 14 days, at 35 days there was no effect on femur breaking strength with interaction between the calcium and phosphorus levels supplied in the breeding diet. The hen diet affected the variables evaluated in the incubation, as well as the production performance of progeny and bone development of the embryos as the chicks.