Protocol for the Extraction of the Harderian gland of Domestic Fowl in the Prehatch Period

Abstract

The Harderian gland, a major para-ocular gland in domestic fowl, is situated in the orbit, ventral and caudomedial to the eyeball. This peripheral lymphoepithelial organ, in conjunction with the spleen, bursa of Fabricius, and caecal tonsils, constitutes a critical part of the avian immune system. Even in adult domestic fowl, the gland possessed the size of a seed of pumpkin. Thus, its extraction is more challenging in the pre-hatch period, wherein its maximum length is less than a centimetre and the gland might often get confused with periorbital fat due to its colour at early embryonic stages. This study was focused to establish a protocol to extract the Harderian gland from chicken embryos at various stages. The gland, grossly was identified by its elongated strap shape and was isolated successfully as early as on day 15 of incubation. The successful step-by-step extraction of the Harderian gland provides valuable tissue samples for further research into its developmental biology and role in avian immune mechanisms.