38 ELEMENTARY TREATISE ON STOCK FEEDS AND FEEDING 



short grass and live on pasture where the horse and ox would 

 starve. The sheep like the horse uses the lips in gathering food. 



The Hog uses the lower lip and teeth in prehending food. 



Drinking. — In drinking, the animal uses the tongue as a piston 

 and pumps up the water to the mouth ; the lips are closed except 

 a small opening, which permits the entrance of the liquid, which 

 is placed under the liquid. The horse and ox use this method in 

 drinking. The horse extends its head while drinking and draws 

 the ears forward at each swallow and back between swallows. 



The dog drinks with the tongue — laps water — by curling the 

 tongue into the shape of a spoon. 



Animals suck by forming a vacuum in the mouth when the 

 lips are closed, increasing the size of the tongue behind and 

 diminishing it in front, the dorsum being applied to the roof of 

 the mouth. 



2. Mastication or chewing is performed between the molar 

 teeth, the large back teeth, or grinders, which reduce and grind 

 the food. The lips, cheeks and tongue help to place and hold 

 the food for grinding. The movements which the jaws undergo) 

 are somewhat different in species of animals. In the horse and 

 ox the movement is not only up and down, but lateral. The 

 herbivora (horse, sheep, goat and ox) can only masticate (chew) 

 on one side at a time; when this side gets tired the process is 

 reversed. The upper jaw of the herbivora is wider than the 

 lower. It takes the horse from five to ten minutes to eat one 

 pound of corn and fifteen to twenty minutes to eat one pound of 

 hay. In the ox mastication is imperfectly performed to start 

 with, but the material is eventually brought back to the mouth 

 by the process of rumination and undergoes thorough re-mastica- 

 tion. 



3. Insalivation. — While the food is chewed and reduced, small 

 ducts and tubes on the sides of the mouth pour out a solution 

 called saliva from the salivary glands. This saliva performs 

 a chemical action on the food by converting the insoluble starch 

 into soluble sugar (maltose), and otherwise prepares these 

 carbohydrates for later digestion in the intestines, etc. Ptyalin, 

 the ferment of saliva, does not change all the starch in the food 



