CATTLE FEEDING. 127 



Tlie Scientific Principles of Cattle Feeding ; 



BY ALFRED B. AUBERT, B. S., 



Professor of Chemistry at the Maine State College. 



Before entering into a discussion of the feeding of cattle, it will 

 perhaps be well to glance at the composition and properties of the 

 important compounds which make up the bulk of the animal, as well 

 as that of the fodder. 



The Animal Body. • 



The body is composed of the following substances : 



1. Water. 2. Nitrogenized substances, called albuminoids. 



3. Fatty substances (ftits). 4. Carbohydrates in small quautit}-. 



5. Mineral substances. 



Albuminoids. Of the nitrogenized substances, or albuminoids, 

 albumin, fibrin and casein are the most important. The best com- 

 mon representative of albumin is the white of the egg, which coagu- 

 lates upon being heated, is soluble in cold water before coagulation, 

 but not so after. It is found in the serum of the blood, from which 

 it can be separated by heating. 



Fibrin is found in blood, and can be obtained by thoroughly wash- 

 ing the clot. It separates from healthy blood when it leaves the 

 living body. It is insoluble in water and forms a stringy mass. By 

 washing the flesh of animals until it becomes colorless, or nearly so, 

 another form of fibrin is obtained called flesh fibrin. Its properties 

 gi'eatly resemble those of blood fibrin. 



Casein can only be obtained from milk bj' the addition of rennet, 

 or an acid. It forms the greater part of the curd. It is not coagu- 

 lable by heat. All the above bodies contain carbon, oxygen, hydro- 

 gen and nitrogen,. in very nearly the same proportions as the follow- 

 ing analyses show : 



Albumin. Fibrin. Casein. Average. 



Carbon 53.5 per ct. 52.8 per ct. 53.5 per ct. 53.3 per ct. 



Hydrogen... 7.1 " 7.0 " 7.0 " 7.0 



Oxygen 23. G " 23.0 " 23.7 •' 23.7 



Nitrogen.... 15.8 " 16.5 " 15.8 " 16.0 " 





