PRINCIPLES FOR FEEDING. 133 



tion; but if protein is lacking in the food, neither 

 the carbohydrates nor any other constituent can 

 take its place. It must be borne in mind that 

 the protein is by far the most expensive, and 

 that it is at an actual loss to the stockman that 

 protein-furnishing food is allowed to take the 

 place of the cheaper carbohydrates in supplying 

 the heat and energy of the animals fed espe- 

 cially since the maintenance of heat and energy 

 requires the greater portion of the food. 



II. Carbohydrates. 



It has been found by actual experiments that 

 when carbohydrates are fed in connection with 

 protein that the protein consumption is lessened; 

 hence, not only is the breaking down of the 

 tissues of the body prevented, but more of the 

 protein of the food is left for the formation of 

 flesh, bone, and other tissues. 



III. Ether Extract. 



The fats perform the same function in the 

 body as do the carbohydrates. Ether extracts 

 are the substances obtained from a " water free " 

 food by ether. Though the terms "ether ex- 

 tract" and "fats" are not strictly interchange- 

 able, they are very often so used. 



i. Heat Value. It has been estimated that 

 one pound of ether extract will produce 2.4 times 

 as much heat as one pound of carbohydrates. 



