4G PRINCIPLES OF FEEDING FARM ANIMALS 



action. It acts as a solvent of the fats and fatty acids and 

 thus assists in their digestion and absorption. Its presence 

 also increases the activity of some of the enzymes of the 

 small intestine, particularly of pancreatic lipase. 



The intestinal juice is secreted by small glands in the walls 

 of the upper and middle part of the small intestine. It 

 contains the enzymes, erepsin, sucrase, maltase, and lactaf^e. 



Erepsin is much more abundant in the intestinal than in 

 the pancreatic juice. It acts upon the proteoses and pep- 

 tones produced by the previous action of pepsin and trypsin 

 upon proteins. It breaks them up further into the amino 

 acids. Its action is the same as that of the erepsin of the 

 pancreatic juice. 



Sucrase acts upon sucrose or cane sugar, sphtting it up 

 into the simple sugars, glucose and fructose. Maltase acts 

 upon the maltose formed by the action of sahvary and pan- 

 creatic amylases upon starch. It spHts it up with the 

 formation of glucose. Lactase acts upon lactose or milk 

 sugar, splitting it up into the simple sugars, glucose and 

 galactose, the latter being quite similar to glucose. 



In addition to the enzymes, the intestinal juice contains 

 a substance called enterokinase, which has the property, 

 when mixed with pancreatic juice, of enormously increasing 

 the action of the latter on proteins. 



Digestion in the Large Intestine. — When the contents 

 of the small intestine pass into the large intestine, they still 

 contain a certain amount of undigested and unabsorbed 

 material. This remains in the large intestine for a consider- 

 able period of time during which the digestive processes 

 started in the small intestine continue their action to a 

 certain extent. In the large intestine of the hog and of the 



