Submitted to: Sturkie’s Avian Physiology, 7th edition
Publication Type: Book / Chapter
Publication Acceptance Date: 4/28/2021
Publication Date: N/A
Technical Abstract: The digestive tract is not only important for nutrient digestion and absorption, but it is the largest immunological organ in the body protecting against exogenous pathogens. The digestive system in birds has adaptations designed to facilitate flight and the length is shorter in most birds relative to mammals. This chapter describes the anatomy and physiology of the digestive tract in wild and domesticated birds showing also similarities or differences in comparison to gastrointestinal tract of mammalian species. Anatomy of components of digestive tract and accessory organs such as pacers or liver is described in details. Physiological properties of gastrointestinal tract including motility, secretion of enzymes and digestion, absorption of nutrients, minerals and vitamins are also presented. Moreover, the age related effects on gastrointestinal function are characterized. The gastrointestinal tract microbiota composition, and its role is described. In addition, the role of gastrointestinal tract as intestinal barrier separating the external environment from the host is presented in this chapter.