FODDEBS AND FEEDS. 157 



The Objects of Feeding. — The objects for which, 

 we feed are : 1. Simply to maintain life ; that is, to 

 replace by food the natural wastes of the body conse- 

 quent upon the simple exercise of the vital functions, 

 as described in the previous chapter; and 2. To main- 

 tain life, and at the same time to increase animal prod- 

 uct or work. It is in carrying out the second object 

 that skill and knowledge are required, in order that 

 the use of the food may result in the greatest and most 

 economical production. 



Animal Products Differ in Their Character and 

 Composition. — The different results accomplished by 

 feeding, as maintenance of life, the production of milk, 

 flesh, fat, wool, etc., are not only different in their char- 

 acter, but in order to secure them at the least outlay of 

 actual nutrients, different proportions of the digestible 

 compounds contained in feeds must be provided. 



In the simple maintenance of life, where there is no 

 gain in flesh, the chief nutrients required are those 

 which best supply the heat and energy necessary to 

 maintain the vital processes ; viz., non-nitrogenous sub- 

 stances : hence it is that hay, straw, and stalks, which 

 possess the requisite bulk, and are rich in this class of 

 substances, serve an excellent purpose in the prepara- 

 tion of maintenance rations for cattle and horses. 



To secure a product rich in protein, as milk or flesh, 

 the feeds must contain a greater proportion of protein 

 than is necessary when the object of feeding is fat, 

 since the digestible protein of the food is the sole source 

 of the protein in the body ; while all the nutrients may 

 contribute to the formation of the fat. In a young ani- 



