Vol. 12, Special Issue 9 (2023)

The present work was conducted to study anatomical characteristics of esophagus in six adult pigs, sheep and goat of both sexes. Esophagus had cervical and thoracic parts in pig, sheep and goat. The length of thoracic part was twice longer than the cervical part in sheep and goat. The width of esophagus increased from cervical part to cardia. The lamina epithelialis consisted of stratified squamous keratinized in pigs, sheep and goat that continued into non glandular portion of stomach in pigs and rumen in sheep and goat. Lamina muscularis was absent in cranial region of the pig's esophagus but present in the middle and caudal region. Whereas it was present throughout the length of esophagus in sheep and goat. Epithelial thickness increased from the pharyngeal junction to the cardia junction in pig, sheep, and goat. In pigs, the glands were numerous in the cranial half but did not extend into the caudal half, while in sheep and goat, no submucosal glands were found in any part of the esophagus. Tunica muscularis comprised striated muscle in cranial two-thirds but subsequently transitioned to smooth muscle in caudal third, with mixed smooth and striated muscle fibers in the pig's while it was composed of striated muscle in sheep and goat. Mucosal layer of esophagus of pig, sheep and goats showed strong PAS and PAS-AB reaction indicating presence of muco-polysaccharides. Sudan black staining revealed lipid substances in esophageal epithelial cells. At pharnygo-esophageal junction, neutral muco-polysaccarrides with positive yielding dark purple acini were observed within submucosal glands of pigs.