88 PRINCIPLES OF FEEDING FARM ANIMALS 



The carbohydrates in the ordinary ration of the corn- 

 belt serve as the principal source of energy to the animal 

 body. True, the protein and fat also may serve the same 

 purpose but, as the former is more expensive and the latter 

 not so plentiful, the carbohydrates usually furnish the larger 

 part of the fuel for the animal body. 



It was stated that the starches and sugars are absorbed 

 in the form of glucose and other simple sugars very similar 

 to glucose, and a small amount of organic acids. They are 

 carried by the blood to the hver which acts as a storehouse 

 and regulator to the supply of glucose in the blood. In the 

 hver, glucose is changed to glycogen or animal starch and 

 stored. Then as needed, the glycogen is reconverted to 

 glucose, which passes again into the blood and is carried to 

 the tissues, where it may be changed back into glycogen and 

 temporarily stored before it is oxidized, or it may be oxidized 

 directly With the hberation of energy and the formation of 

 carbon dioxide, which is excreted through the lungs, and 

 water, which is excreted mainly through the urine and to a 

 shght extent through the lungs and perspiration. The crude 

 fiber is absorbed in the form of salts of organic acids, which 

 probably are oxidized in the tissues with the liberation of 

 energy and the formation of carbon dioxide and water. 



If there is any surplus of carbohydrates above the needs of 

 the body for energy, it may be converted into fat and stored 

 in the body. It was long contended that carbohydrates could 

 not serve as a source of body fat, but it has been proven that 

 they do have this function. In fact, the carbohydrates, owing 

 to the high cost of protein and the scarcity of fat in ordinary 

 rations, are the most important source of body fat in most 

 feeding operations. This is true especially in the corn-belt. 



