TURK 2025

The ileum is the final part of the small intestine and plays a crucial role in digestion in birds. It not only absorbs essential micromolecules through epithelial villi but also functions as a key immune organ. It contains Peyer’s patches (B-lymphocyte-rich lymphoid follicles), scattered T cells, and macrophages. Although extensively studied in humans and various mammalian and avian species, macro- and micromorphological data on the ileum of Phasianus colchicus mongolicus (Mongolian pheasant) are lacking in the current literature. This study aims to define the anatomical, histological, and morphometric characteristics of the ileum in domesticated Phasianus colchicus mongolicus. The primary material consisted of ileum samples from seven 11–12-month-old pheasants euthanized via decapitation. Prior to dissection, each bird was weighed, and a thorough anatomical and morphometric examination of the digestive system was conducted, with a focus on the ileum. Length and width measurements were obtained using calipers (accuracy: 0.05 mm) and a measuring tape (accuracy: 0.1 mm). Tissue samples were fixed in 10% formalin and processed for histological analysis. Sections of 4 µm thickness were stained with hematoxylin-eosin and subjected to Schiff’s iodine reaction to detect glycogen. Statistical analysis was performed using IBM SPSS Statistics 22. Macroscopic analysis revealed that the ileum had a slightly firm wall with a reddish-gray hue. Dense nodules were particularly abundant near the cecal junction. The average ileum length was 11.643 ± 0.4225 cm. Microscopically, the organ comprised serosal, muscular, and mucosal layers. Within the submucosa, lymphoid follicles, T lymphocytes, macrophages, eosinophils, and other immune cells were identified. The glycocalyx, goblet cells, and glandular epithelial cells exhibited positive reactions in Schiff’s test. These findings contribute valuable data to the field of avian morphology and provide a foundation for future research.