THE DIGESTIVE SYSTEM 91 



Factors influencing gross digestion are of several kinds. 

 Those of most importance are: 



The Quality of the Ration. — Coarse, woody feeds like corn 

 stalks, overripe hay, straw, etc.; containing much cellulose are 

 difficult to digest. If they are cut with a feed cutter before being 

 fed, they are more easily and completely digested. Rations of 

 any kind that are poor in quality are unpalatable and retard 

 digestion. Some feeds have a constipating effect, e.g., cottonseed 

 meal, while others have a laxative effect, e.g., linseed meal. 



The Quantity of the Ration. — Too much feed of any kind 

 hinders the digestive process. It is believed, however, that with 

 herbivorous animals a fairly bulky grain ration gives better 

 results than one occupying less space. This is true in less degree 

 of roughages. 



Variety in the Ration. — If feeds are mixed before feeding ac- 

 cording to determined standards, they are more palatable and 

 the work of the digestive organs is distributed and digestion facili- 

 tated. An exclusive ration of any kind is not so readily digested, 

 especially if fed over a long period, as one properly mixed and 

 balanced. There is evidence that some kinds of feed influence 

 the digestibility of others. 



The Completeness of Mastication. — Incomplete mastication 

 from any cause results in the introduction of too large food parti- 

 cles to the stomach and hinders digestion. The more perfectly 

 foods are masticated the greater the amount of nourishment 

 afforded the animal, because less energy is expended to digest 

 them. Therefore, the longer it takes an animal to eat a meal of 

 dry feed, the more economically can it be kept. Various devices 

 or automatic feed controllers are in use to compel horses to eat 

 more slowly, but none has proved to be entirely satisfactory. A 

 few cobblestones placed in the bottom of the feed manger tend 

 to prevent bolting of food. 



The Idiosyncrasy of the Animal. — This refers to the disposi- 

 tion of the individual. Some animals are much more efficient 

 machines for converting the stored energy in their rations into 

 free energy than others. This is one reason why certain animals 

 are "easy keepers," while others are "hard keepers" and fail 

 to thrive even under good living conditions. The factors in- 

 volved are of a physiologic nature. An examination of the com- 

 position of the excreta of different animals of the same breed 



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