Department of Anatomy and Histology, Faculty of Veterinary Medicine, King Salman International University, Ras Sudr, Egypt.
Department of Anatomy and Embryology, Faculty of Veterinary Medicine, South Valley University, Qena, Egypt.
BMC Vet Res. 2024 Sep 23;20(1):428. doi: 10.1186/s12917-024-04147-z.
Pigeons (Columba livia) are mainly raised as a source of animal protein, racing, leisure and as an experimental animal. The present study investigated the morphology of the esophagus in the young and adult domestic pigeon, Columba livia domestica.
Ten young and ten adult, normal, and healthy pigeons were collected from the local breeders. Samples from different parts of esophagus and crop were examined grossly, by stereomicroscopy, scanning and light microscopy.
The esophagus consisted of a long cervical part, a crop, and a short thoracic part. The crop was represented by a thin-walled outpouching with two lateral diverticula. The mucosa presented wavy fine folds in the cervical esophagus, irregular folds in the lateral diverticula giving it a corrugated appearance, and prominent longitudinal folds with several gland openings in the middle and lower parts of the crop, as well as in the thoracic esophagus. The density of gland openings was higher in adult pigeons than that in young pigeons. The mucosa of the esophagus was lined by non-keratinized stratified squamous epithelium. The shape, height, and branching of the mucosal folds differed between young and adult pigeons. Mucous-secreting alveoli were detected in the middle part of the crop as well as in the thoracic esophagus, but not in the cervical esophagus or lateral diverticula of the crop.
The variations between the young and adult pigeons suggest a functional adaptation of adult pigeons to their diet compared to young pigeons.
鸽子（Columba livia）主要作为动物蛋白的来源、赛鸽、休闲和实验动物而被饲养。本研究调查了国内鸽子（Columba livia domestica）幼鸽和成年鸽食管的形态。
从当地饲养者那里收集了 10 只幼鸽和 10 只成年、正常和健康的鸽子。通过体视显微镜、扫描和光学显微镜检查了食管和嗉囊不同部位的大体标本。
食管由长的颈段、嗉囊和短的胸段组成。嗉囊是一个薄壁的外突，有两个侧憩室。颈段食管的黏膜呈波浪状细皱襞，侧憩室呈不规则皱襞，呈波纹状，中下部嗉囊和胸段食管有明显的纵向皱襞，并有几个腺体开口。成年鸽子的腺体开口密度高于幼鸽。食管黏膜衬有非角化复层扁平上皮。幼鸽和成年鸽的黏膜皱襞形状、高度和分支不同。在嗉囊中部和胸段食管中检测到分泌黏液的肺泡，但在颈段食管或嗉囊侧憩室中没有检测到。
幼鸽和成年鸽之间的差异表明，与幼鸽相比，成年鸽的饮食功能适应了它们的饮食。
