Morphophysiological Study of Gastrointestinal Tract of the Donkey (<i>Equus asinus</i>)

In most of the developing countries, donkeys are used to carry goods and water and to guard herds as a livestock guardian.Donkeys possessed a good digestive system and are being offered only low-cost fibers diet like hay and straw.Despite the biological potential of the donkey, only a few studies have focused on the morphophysiological aspects of their digestive system.A series of tubular organs and associated glands are present in the digestive system.Although generally the morphology of the donkey digestive system is comparable to the horse, few dissimilarities exist among such species.In this chapter, we tried to highlight the anatomy, histology and physiology of the digestive system of domestic donkeys including tongue (mucosa, papillae, muscle, taste buds), teeth, pharynx, esophagus, stomach, saccus cecus, descending part, an ascending part and transversal part of the duodenum, jejunum, ileum, cecum, colon (right dorsal and ventral; left dorsal and ventral), rectum and anal canal.The microarchitecture of the tunica mucosa, next to the lumen, is focused upon.Morphology of the large accessary digestive glands viz.salivary gland, liver and pancreas were also highlighted.These structures are situated away from the gut-tubular system but are attached to its lumen through their specified duct system.Furthermore, peculiar microstructures of the internal layers, immune system and microbiome of the gut were correspondingly highlighted in the chapter.