118 ILLINOIS STATE DAIRYMEN'S ASSOCIATION 



tein are the legumes such as alfalfa, clover and peas, and vari- 

 ous meals as oil meal, cottonseed meal, gluten meal. In the ani- 

 mal body the chief use of protein is to build up muscle, and to 

 form the casein of milk. It is important that the required 

 amount of protein be fed since no other .constituent can take its 

 place in the formation of muscle and milk. 



Carbohydrates. 



Carbohydrates is the name given a group of feed constitu- 

 ents which contain no nitrogen. In this group are found starch, 

 sugar and crude fiber. Carbohydrates furnish the energy need- 

 ed to perform the bodily functions. They are also the source 

 of the heat of the system. Carbohydrates also normally furnish 

 the constituents for forming milk sugar and the fat in milk. 



Fat. 



In the body fat performs the same function as do carbohy- 

 drates, the chief difference being that fat is a more concentrated 

 form of food, one pound of it being equal to 2.4 pounds of car- 

 bohydrates. The two are interchangeable; that is, one can be 

 made to serve the purpose of the other. 



Classes of Feeds. 



Inasmuch as protein and carbohydrates are the two constitu- 

 ents with which the feeder is most concerned, it will be of value 

 to roughly classify some of the most common feeding stuffs into 

 two classes : 



1st. — Those which contain a large per cent of protein. 



2nd. — Those which are chiefly carbohydrates. 



The feeder can easily see that in order to balance the ra- 

 tion properly it must be made up of feeds from both classes. 



