The Digestive System
This week we covered the horse’s digestive system. The horse is a non-ruminant animal. Non-ruminant animals (also called monogastric) have a single-chambered stomach. As opposed to ruminants, who use bacteria in the rumen to break down food, non-ruminants use saliva in the mouth to start the digestion process. Horses are non-ruminants as are humans. Ruminant animals have a four-chambered stomach. The food is chewed and swallowed into the rumen where bacteria works to digest the food before it is regurgitated and chewed again. Other examples of ruminant animals include cattle, sheep, goats, giraffe, and other deer-like mammals.
The digestive system is made up of two sections — the foregut and hindgut. The horse’s foregut includes the stomach and small intestine. The stomach is located in the front area of the abdominal cavity and its purpose is to digest food. The stomach lining secretes gastric juices to break down food. Then the organ’s muscles contract to move food along to the small intestine. The small intestine is where nutrients will start to be absorbed and is comprised of three segments: the duodenum, jejunum, and ileum.
The horse’s hindgut includes the cecum and colon. The cecum and large colon contain bacteria which work to break down the high-cellulose diet of the average horse. Both cecum and large colon are long portions of the alimentary canal to allow for maximum time for cellulose digestion. The small colon allows moisture to be reabsorbed into the system. This is also where fecal balls form before expulsion through the rectum.