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ILLINOIS DAIRYMEN'S ASSOCIATION. 



protein contained in the different feeds; first, because it is us- 

 ually deficient, especially in feeds for dairy cows; second, be- 

 cause no other class of substances can perform the same functions. 



Carbohydrates. 



Carbohydrates is the name applied to the carbonaceous group 

 of substances such as starch, sugar, and the woody parts of plants 

 known as crude fiber. This group forms the larger part of the 

 food consumed by animals, as we shall see later. Carbohydrates 

 furnish heat to keep up the body temperature, energy to perform 

 the body functions and the muscular activity, and if fed in excess 

 of these demands fat may be stored up in the body. In the case 

 of the dairy cow, carbohydrates, besides supplying the above re- 

 quirements, furnish the constituents for forming milk sugar and 

 fat in milk. 



Fat. 



Every one is familiar with fat in its different forms; as, 

 tallow in the steer, lard in the hog, and fat in milk. In <.L',n 

 there is about 4.3 per cent of fat, or oil, and in flaxseed a much 

 larger proportion, while in most of the rough fodders there is 

 comparatively little. Fat in the food nourishes the body in exaccly 

 the same way as do carbohydrates, namely, furnishes heat and 

 energy and forms fat. The chief difference between fat and car- 

 bohydrates is that the former is a more concentrated form of 

 food, one pound being equal to 2.4 pounds of carbohydrates. It 

 should be remembered that fat and carbohydrates are interchange- 

 able, that is, wdiichever one is in excess may take the place of the 

 other, but it must also be borne in mind that however great the ex- 

 cess of carbohydrates and fat in the ration, no more muscle can be 

 formed in the body, or casein produced in the milk than there is 

 protein in the food supplied. In other words, where protein is in 

 excess it can take the place of carbohydrates and fat, but no 

 amount of carbohydrates and fat can take the place of protein in 

 the least degree. 



