Vitamin D3 in ovo influences the bone mineral density of post-hacth chicks

The biological function of cholecalciferol is to act on bone metabolism and skeletal growth, more specifically, regulate calcium metabolism and provide nutritional support genetic so that birds can express their maximum performance. The cholecalciferol (vitamin D3) present in the egg yolk is metabolized by the embryo during incubation, to be used in the formation of the skeleton of the chicks. Based on this, the aim of the research was evaluate the effect of different levels of vitamin D3 injected in fertile eggs of broiler breeders on bone mineral density post-hatch chicks. The experimental design was completely randomized, with 600 fertile eggs of broiler breeders Cobb500 distributed in five treatments: not injected eggs (control); eggs injected with 100 mL of olive oil; eggs injected with 1.2ug; 2.4ug and 3.6 ug of vitamin D/100 mL of olive oil, totaling 120 eggs per treatment. The eggs were injected at eighth day of incubation. The data were analyzed using the General Linear Model (GLM) procedure of SAS (R). The mineral composition and bone mineral density of femurs and tibias of post-hatch chicks were evaluated. There was not effect of the Vitamin D3 levels on the percentages of calcium, phosphorus and ash of the femurs and tibias. However, bone mineral density showed an effect among the control and levels of vitamin D3, with higher density for control treatment, still, there were quadratic and cubic effect to tibias and femurs to the 1.4ug and 1.52ug of vitamin D3 levels, ideals to maximize the bone mineral density of post-hatch chicks. We concluded that, it is feasible the use of vitamin D3 in fertile eggs for increasing bone density, however, large amounts can show unsatisfactory results and also, possibly, can to be harmful to hatchability.