protein, and 928 lbs. digestible carbohydrates, it would have 9.4 

 times as much carbohydrates as protein or 1 : 9.4 which is its nutritive 

 ratio. 



DIGESTION. 



^Yhat digestion is : Digestion is the changing of feeds in the 

 stomach and intestines into soluble and diffusible substances-, that 

 can be taken up by the blood. The process briefly stated, is as 

 follows : The feed is chewed in the a.outh, and thoroughly moistened 

 by the saliva. The moistening of the feed thus enabling it to be 

 easily swallowed — is the [)rincipal value of this secretion. The 

 stomach of the ruminant has four divisions. The slightly chewed 

 feed passes to the large first stomach or paunch, and then into the 

 smaller second division. The food, thus softened, is returned from 

 the second stomach to the mouth and more thoroughly masticated 

 and then passes to the third stomach. This third stomach has numer- 

 ous folds, between which the food is pressed, and the soluble portions 

 directly resorbed. It then passes into the fourth stomach where the 

 ordinary process of digestion begins in the same manner as in animals 

 having a simple stomach. The feed is here subjected to considerable 

 motion and is acted on by the so-called gastric juice, the active prin- 

 ciples of which are pepsin and hydrochloric acid. This action of 

 these substances changes the protein into a soluble form called pep- 

 tone. Neither the fat nor the carbohydrates undergo any change in 

 the stomach. 



Small amounts of some kinds of protein are so changed in the 

 stomach as to be taken directly into the blood. But by far the larger 

 part of the food now termed chyme, goes from the stomach into the 

 intestines, to be further acted upon. The digestive fluids of the in- 

 testines are the bile or gall of the liver, the pancreatic juice of the 

 pancreas, and the intestinal juice. The chief use of the gall is to 

 divide the fat into very minute globules i. e. to emulsify it. The bile 

 also aids in the resorption of the fat. The pancreatic juice con- 

 tains a ferment called trypsin which acts powerfully upon the various 

 forms of protein, changing any that escape the action of the pepsin 

 of the stomach, into peptone, and still further converting a part of 

 the peptone into other simpler substances. Another, no less import- 

 ant ferment is the ptyalin, which converts a considerable part of the 

 starch and similar carbohydrates into sugar (maltose) . The pancre- 



