108 The Feeding of Animals 



important office, for it is a necessary preparation to the 

 act of swallowing. With large ruminants, the quantity 

 of saliva required for this purpose is large, as is evident 

 when we remember that an ox or cow may consume in 

 one day 24 pounds of very dry hay and grain, and that 

 rumination goes on much of the time while the animal 

 is not eating. It is estimated that oxen and horses se- 

 crete from 88 to 132 pounds daily, an apparently enor- 

 mous quantity of liquid for secreting organs no larger 

 than the salivary glands to supply. 



THE STOMACH 



When the food leaves the mouth, it passes down the 

 gullet (oesophagus) into the stomach. The only modi- 

 fications it has suffered up to this point are its reduction 

 to a finer condition and a slight action of the mouth 

 ferment upon the starch, an influence which doubtless 

 continues in the stomach for a larger or shorter pe- 

 riod, according to circumstances. After the food is 

 swallowed changes of another kind begin sooner or 

 later, affecting the protein compounds especially. 



Before considering gastric digestion from a chemi- 

 cal point of view, we should become acquainted with 

 the widely differing structure of the stomachs of the 

 various farm animals. Those of the ox and horse are 

 greatly unlike. The stomach of the ox, and of all other 

 ruminants, consists of four divisions or sacs, whereas 

 with the horse and pig it is made up of a single sac. 



The ruminant stomach is really quite a complicated 

 affair, and the way in which it disposes of the food is 



