94 THE FEEDING OF ANIMALS 



on starch are called diastases. Enzyms that split fats are 

 designated as lipases and those acting on proteins to pro- 

 duce proteoses are designated as 'proteases. 



THE ALIMENTAEY CANAL 



The digestion of food is accomplished in the alimen- 

 tary\ canal, a duct that extends from the mouth to the 

 anus. 



130. Parts of the alimentary canal. — The succession of 

 the various parts of this canal is as follows: the esophagus, 

 stomach, small intestine (duodenum) and the large intes- 

 tine (colon). 



The length of the intestines in the several species of 

 farm animals is very great as compared with the length 

 of the body of the animal, as the following figm-es show: 



Sheep, ratio length of intestine to length of body . 26 times 



Ox, ratio length of intestiae to length of body . . 20 times 



Horse, ratio length of intestine to length of body . 12 times 



Dog, ratio length of iQtestine to length of body . 3 times 



The food is pushed along the intestinal canal by a 

 muscular movement of the walls of the intestines known 

 as peristalsis, which passes from stomach to rectum, being 

 slower in the large intestine than in the small. During this 

 passage there occurs both the digestion of food and the 

 absorption through the walls of the canal of the digested 

 materials. 



THE MOTJTH 



131. Mastication. — ^The first step in the digestion of 

 fodders and whole grains is to reduce them to a much 



'finer condition. This is done in the mouth, the teeth being 

 the grinding-tools.* Sometimes the cutting or grinding is 



♦This is not true of hens, turkeys, and other fowls. 



