Journal of Veterinary and Applied Sciences

Abstract
The cattle egret (Bubulcus ibis), a highly adaptable and ecologically successful species, is one of the understudied bird species. This study evaluated the gross morphology, morphometry and histological organization of the lower respiratory tract of the cattle egret. Six apparently healthy adult cattle egrets (three females and three males) were used for the study. Live weights of the birds were measured prior to euthanasia. Thereafter the components of the lower respiratory tract (trachea, primary bronchi and the lungs) were dissected, separated and weighed. Their lengths and diameters were also measured. Tissue samples from the three segments were routinely processed for histological examination, and stained using haematoxylin and eosin. Results showed that the trachea of the cattle egret was a translucent tubular structure composed of complete cartilaginous rings with a mean length of 163.37 ± 2.06 mm in females and 174.0 ± 3.46 mm in males. The mean number of tracheal rings in the females were 156.33 ± 1.20, while the mean number of tracheal rings in the males were 157.33 ± 1.45. The trachea bifurcates into left and right primary bronchi which are short and supported by C-shaped cartilaginous rings. The lungs were shiny pinkish, lobed and wedged shaped organs, which firmly adhered to the thoracic wall, with rib impressions that form costal sulci on the dorsal surface. Histologically, the trachea and bronchi were lined by ciliated pseudostratified columnar epithelium, while the lungs, parabronchi, atria, infundibula and air capillaries were lined by simple squamous epithelium. The lower respiratory tract of cattle egret conforms to the general avian model. There was no significant sexual dimorphism in the gross morphology, morphometry and histology of the lower respiratory system of the cattle egrets studied.

Keywords: Cattle egret (Bubulcus ibis); Lower respiratory tract; Trachea, primary bronchi
and the lungs; Gross morphology; Morphometry; Histology.

How to cite this article:
Rilwan MF, Nzalak JO and Zubairu M (2026). Gross, morphometric and histologic study of the lower respiratory tract of the cattle egret (Bubulcus ibis). Journal of Veterinary and Applied Sciences, 16(2): 1597 – 1606.

*Correspondence: E-mail: dr01mansur@gmail.com Phone: +2347034980639