Morphologic Evaluation of the Fertilized and Unfertilized Ostrich Egg during the Early Stages of Development (MRI Analysis)

The magnetic resonance imaging (MRI) technique permits to monitor the development of the embryo in vivo without causing any developmental defects. Although increasing application of MRI imaging are predicted in veterinary sciences, there is little information available about MRI studies of avian embryos and their eggs. The objective of the present study was to evaluate the ostrich embryonic development in the first 18 days of incubation using the MRI technique. Fertilized and unfertilized ostrich eggs were incubated in standard condition. The eggs were removed from the incubator on days 2 to 18 post-incubation and exposed to 1.5 Tesla magnetic fields. The results showed that the structures of unfertilized eggs remained fairly constant over the 18 days of incubation but it was a significant change in fertilized eggs from 4th day. At early stages, the considerable structures of the eggs such as wight/yellow yolk, albumen, air cell, latebra and neck of the lateral were revealed very clearly but the embryo and blood vessels could not be visualized until the day 6 post-incubation. Some details, such as eyes and amniotic sac, were also seen on day 10 of development. At later stages, the spherical shape of the yolk becomes completely distorted, it was distributed across the middle of the egg and the yellow and white yolk layers were disappeared. Based on the findings, it is concluded that MRI is a suitable technique for following the development of a live ostrich embryo and its egg components at the first half of the incubation period.