The horse's digestive system consists of those organs concerned with digestion, or the turning of complex food material such as hay, grass and corn etc, into simple substances such as carbohydrate, protein (amino acids), fatty acids, etc, which can be used by the body for energy, storage or body building processes. The organs consist of alimentary tract which is the tube extending from the mouth to the anus and know also as the gut, intestines or aliamentary canal, and the accessory organs such as the teeth, tongue, salivary glands, liver and pancreas.
The special characteristics of the horse's mouth are highly prehensile lips for gathering food which work in conjunction with the sharp front teeth when cropping grass, and the labile tongue which conveys the food to the back teeth. These have table-like surfaces crossed by ridges that form an ideal grinding surface between the upper and lower jaws.
Ducts which discharge digestive juices from the parotid mandibular and sublingual salivary glands open into the mouth. The roof of the mouth is formed by the hard palate in front, which continues into the soft palate behind. The soft palate forms part of the pharynx where the air passages and digestive tract cross one another.
As a horse swallows, the food crosses the pharynx and enters the gullet or oesophagus, from where it is conveyed to the stomach and thence to the small intestines, large colon, small colon and rectum.
The alimentary tract, from the stomach to the rectum, together with the pancreas and liver (glands which contribute more digestive juices and bile) are contained in the abdominal cavity. This can be described as a large `box', the sides of which are the diaphragm in front, the muscles below the spine forming the top, and the muscles of the...