Turk D E
Poult Sci. 1982 Jul;61(7):1225-44. doi: 10.3382/ps.0611225.
The anatomy of the avian GI tract is believed to markedly influence the utilization of feed processed by it. The anterior portion of the tract is adapted for ingestion, storage, and partial digestion of starch and proteins. The structure of the avian intestine is similar to that of other monogastrics except that lacteals are not found. Damage to the intestinal epithelium may decrease nutrient absorption, whereas epithelial replacement may result in improved nutrient utilization. Mitochondrial and other organelle changes are associated with changes in nutrient absorption. The avian intestine has a prominent glycocalyx overlying the microvilli. The avian liver lacks the true lobular structure of the mammalian liver. The hepatocytes are arranged in plates two cell layers thick around the bile caniculi. The avian pancreatic structure contains two main and two smaller lobes containing acinar cells, which secrete digestive enzymes into the the pancreatic ducts, and endocrine cells, which secrete hormones into the general circulation. The structure of the colon is similar to that of the intestine except for poor enervation.
禽类胃肠道的解剖结构被认为对其所处理饲料的利用有显著影响。消化道的前部适合摄取、储存以及对淀粉和蛋白质进行部分消化。禽类肠道的结构与其他单胃动物相似，只是没有发现乳糜管。肠道上皮受损可能会降低营养物质的吸收，而上皮细胞的更新则可能提高营养物质的利用率。线粒体和其他细胞器的变化与营养物质吸收的变化相关。禽类肠道的微绒毛上覆盖着一层明显的糖萼。禽类肝脏缺乏哺乳动物肝脏真正的小叶结构。肝细胞围绕胆小管排列成两层细胞厚的板状结构。禽类胰腺结构包含两个主要叶和两个较小叶，其中含有腺泡细胞（将消化酶分泌到胰管中）以及内分泌细胞（将激素分泌到全身循环中）。结肠的结构与肠道相似，只是神经支配较差。
