Abstract

The current study examined the intestine of the domestic pigeon (Columba livia domestica) using gross morphology, scanning electron microscopy (SEM), light microscopy, and morphometric analysis. Pigeon intestine was 70-75 cm long. The duodenum is a prominent U-shaped loop that enclosed pancreas was 8-10 cm long. The jejunum measures approximately 30-33 centimeters. The ileum measures approximately 10-12 centimeters. The colon measured about 7-8 centimeters. Our SEM analysis revealed that the jejunal villi were shaped like tongues and fingers. Jejunum has two types of villi, with an average thickness of 50.4 µm. The small intestine mucosa was composed of simple columnar epithelium and goblet cells. Jejunum sections revealed a moderate PAS staining reaction within the intestinal villi's goblet cells. Jejunum sections stained with Alcian Blue (AB, pH 2.5) revealed a moderate (++) distribution of acid mucins and glycoproteins in the goblet cells of Lieberkühn's crypts and along the lateral surfaces of the intestinal villi. The intestine was slightly stained in the lamina propria and significantly stained in the serosa. The colon's villi were lined by simple columnar epithelium with goblet cells and were nearly identical in width at the base and tips. At the bases of these villi, intestinal crypts were discovered to have some villi of different heights, and the muscularis mucosa was defined at the colon wall. The present findings establish a comprehensive anatomical and histomorphometric baseline for the pigeon intestine, supporting future experimental, comparative, and applied avian research.

Key words: Pigeon, intestine, Anatomy, SEM, light microscopy.