The intestine (Latin: intestinum commune) is the longest part of the digestive tract. It is a coiled tube that extends from the exit of the stomach to the anus. The intestinal canal is divided into small intestine (lat .: intestinum tenue) and large intestine (lat .: intestinum crassum). The small intestine is divided into the duodenum, the jejunum and the ileum. The large intestine consists of the parts caecum, colon and the rectum. In contrast to humans, the appendix is clearly developed in slaughter animals. The length of the intestine differs greatly depending on the species. In cattle, the intestinal length varies between 30 and 60 m, in sheep between 20 and 40 m and in pigs between 20 and 25 m. These are leaf- to finger-shaped elevations of the small intestinal mucosa. The intestinal villi are covered with intestinal epithelial cells with microvilli and thereby enlarge the intestinal surface considerably. The surface enlargement is used for food absorption.
The intestine consists of three layers.
- Inner layer: mucous membrane, consisting of intestinal villi and glands
- Middle layer: Muscle skin, consisting of longitudinal and transverse fiber layers, causes the intestinal contents to move
- Outer layer: epidermis (serosa or ligament), smooth and thin
The microorganisms that are originally in the intestine must be eliminated quickly and effectively during cleaning, as they could otherwise negatively affect sausage production later on. For this purpose, the epidermis, the mucous membrane and the inner muscle layer of the intestine are mechanically removed from the sheep casing. All that remains is a thin and slightly transparent middle muscle layer (the submucosa). Only this is processed into the sheep casing (Saitling).