Study of embryos stages of development for estimation of day of death in red-legged patridge (Alectoris rufa rufa L.)

The exact determination of the death age of embryos could be important in determining causes of embryonic mortality. For this reason, a study on partridge chick embryo development was useful. To monitor red-legged partridge (Alectoris rufa rufa) embryo development, we incubated 80 eggs, chosen randomly, all laid in the same day of the 9th laying week. Every day during the incubation period 2 eggs were opened, embryos were photographed, described in a macroscopic manner and several measurement were carried out. In order to estimate embryo age, we can divide the whole development process into two main periods. The first period is mainly characterised by formation of new organs (embryonic or extra embryonic or body portions), going from the first to 17th incubation day. The second period is characterised by growth of body organs and limbs from the 18th day to the 24th. The study also elucidated enough development stages to estimate embryo age within an approximation of about one day.