The ostrich (Struthio camelus) blastoderm and embryo development following storage of eggs at various temperatures

Abstract

1. The gross morphology of blastoderms in fresh unstored ostrich eggs and in eggs subjected to different regimen of storage and incubation was studied. Then the effects of storage duration of eggs (1, 2 and 3 weeks) and storage temperature (15, 20 and 25°C) on blastoderm and embryo development were investigated.

2. Only incubation following overnight storage at 18°C advanced blastoderm development (1·5-fold increase in diameter) to a stage comparable to hypoblast.

3. Storage of eggs at 15 or 20°C did not affect blastoderm stage and size whereas, at 25°C, the blastoderm doubled in size and appeared to have advanced to a primitive streak stage. Embryo development was reduced after 2 weeks of storage regardless of the storage temperature.

4. After oviposition and during pre-incubation storage the ostrich blastoderm develops progressively over time in a temperature-dependent manner towards the hypoblast stage and beyond but the viability of the blastoderm and embryo development is seriously compromised by 2 weeks of storage.

Acknowledgements

We thank Chris Bray from Olympus Australia for kindly providing the image capture and analysis equipment and the Rural Industries Research and Development Corporation (Australia) for funding this work. J.O.H. was on research visit under the Memorandum of Understanding between the University of Western Australia and the Institute of Genetics & Animal Breeding of the Polish Academy of Sciences. We also thank Dr Murry Bakst for his helpful suggestions.