Digestion starts in the mouth where chewing and saliva secretion occur. Functions of saliva include lubrication, buffering, amylase, lipase and urea. Digestive secretion of the stomach include HCL, pepsinogen, mucus and renin. Most extensive digestion and absorption in the non-ruminant occurs in the small intestine. This is divided into the duodenum, jejunum and ileum.
Pancreatic secretions occur in the duodenum.
Four secretions occur in the duodenum. These include the duodenal juice, bile, pancreatic juice and succus entericus. Secretion of pancreatic juice occurs in 3 stages. The first stage involves the stimulation of bicarbonate flow from the pancreas. This is caused by acid entering the duodenum from the stomach.