Assessment of the morphological development of the caecal tonsil in turkey (Meleagris gallopavo)
The post hatch (PH) development of the caecal tonsil in turkey (Meleagris gallopavo) was studied from day (D) 1 post-hatch to D 140. The tonsils appeared as nodular structure on the surface of the proximal part of the caecal base. The caecal wall of all ages was composed of four histological layers. The mucosa consisted of simple columnar epithelium with goblet cells. At D 1 PH the tonsil was composed of minute aggregates of proliferating lymphoid cells. By D 7, Leiberkuhn glands were observed in the stroma of the tonsil, and at D 28, nodules packed with lymphocytes and some plasma cells were observed. Between D 28 and D 133, there were gradual increase in dimension of the tonsils and proliferation of lymphatic nodules. At D 140, there was depletion of lymphatic nodules especially at the apical regions bordering the caecal lumen, and increase in thickness of the intervening connective tissue was very obvious.
Key words: caecal tonsil, turkey (Meleagris gallopavo ), morphology, post-hatch, development