The gastrointestinal tract of an avian is unique in comparison to those of mammals; it contains an intestinal tract that is shorter than that of mammals.
The digestive tract begins with the mouth. Chickens don’t have teeth or jaw muscles, instead, they have a lightweight beak to swallow food particles whole. These particles are later broken down by the ventriculus, or gizzard, which is located within the body cavity. The upper beak is covered in hard keratin.
Next is the tongue, which is used for collecting, moving, and swallowing food. The tongue, which is covered in lateral barbs, is used to brush food to the back. Salivary glands are less developed in birds but are present at the roof of the mouth; they secrete mucus which lubricates the food and allows it to move down the esophagus. Taste buds are located on the upper beak and are also in small numbers on the anterior of the tongue; chickens have up to 300 taste buds. Behind the tongue is the laryngeal mound that contains a narrow slit opening that goe