Minimal invasive localization of the germinal disc in ovo for subsequent chicken sexing using optical coherence tomography

ABSTRACT Reason for using optical coherence tomography (OCT) to locate the germinal disc is the questionable and ethically alarming killing of male layer chickens because for the layer line only the females are necessary. To avoid this and to protect the animal rights, the sex of the fertilized chicken egg has to be determined as early as possible in the unincubated state. Because the informati on whether the chick becomes male or fema le can be found in the germinal disc an accurate localization for sexing is essential. The germinal disc is located somewhere on top of the yolk and has a diameter of approximately 4 - 5 mm. Different imaging methods like ultrasonography, 3D-X-ray micro computed tomography and magnetic resonance imaging were used for localization until now, but found to be impractical. The goal of this study is to prove if OCT can be a moderate approach for the precise in ovo localization. Because the eggshell is an impenetrable barrier for OCT and to mini mize the penetration of germs a very sm all hole is placed in the eggshell and a fan-shaped optical scanning pattern is used. Keywords: OCT, fan-shaped optical scanning pattern, scanning through a very small hole, questionable and ethically alarming killing of male layer chickens, sexing of the fertilized unincubated chicken egg, localization of the germinal disc