192 BEEF PRODUCTION 



fiber than do others, for example, horses. (2) Not only 

 is there a difference in classes of animals as to their di- 

 gestive capacities, but there are differences in animals 

 of the same class in this regard. In other words, some 

 animals are more economical producers of animal pro- 

 ducts than others. 



Processes of Digestion and Assimilation. — To be of 

 any use, the digested food must be assimilated by the 

 animal. The process of assimilation consists in the 

 taking up or absorption of digested food particles, which 

 are conveyed by the blood to every part of the animal. 

 A general knowledge of where the various food nutrients 

 are digested is desirable; hence, a brief reference to the 

 subject seems pertinent. 



The changes which take place in food during the 

 processes of digestion are mainly chemical; but the first 

 change or process is a mechanical one — that of masti- 

 cation, the process during which the food is broken or 

 ground up into fine particles, rendering it more suscep- 

 tible to the chemical action of various juices with which 

 the food particles come in contact during its passage 

 through the alimentary canal. The only food nutrient 

 that is partially or wholly digested by the action of the 

 digestive ferments with which the masticated food is 

 brought in contact in the mouth is a portion of the starch 

 constituent of carbohydrates. Whether the amount 

 digested is large or small depends upon the thorough- 

 ness of mastication and the length of time the food re- 

 mains in the mouth. Under ordinary conditions, since 

 the food remains there but a short time, the amount of 

 starch digested is small. 



The remainder of the digestible starch is digested 

 mainly in the intestines. In general, then, we may say 

 that carbohydrates are digested partly in the mouth, but 

 mainly in the intestines. 



The stomach, by the action of the different ferments 

 in the gastric juice, the digestive agent with which the 

 food comes in contact in the stomach, digests the greater 



