230 THE PRINCIPLES OP AGRICULTURE 



with the expenditure of but a small part of its 

 own proper substance. Thus the starch and 

 sugar in the diet contribute not only to main- 

 tain heat and to lay up fat, but also to render 

 possible a large expenditure of muscular energy 

 and work. 



66. Applications to practice 



424. Such expenditure of food and muscular 

 energy in producing heat and work prevents the 

 laying out of the same capital for other uses, 

 such as growth, fattening or milking. In do- 

 mestic animals, which can be profitably kept 

 only when adapted to special uses, expenditures 

 in other directions must be limited as far as may 

 be in keeping with the maintenance of health. 



425. For rapid fattening, rest and warmth and 

 seclusion are favorable. Even the milch cow, put 

 in the stable in good health, may be made to 

 give more milk for a time when kept idle in a 

 warm stall than when turned out to gather her 

 food from a pasture. This, however, cannot be 

 safely carried to extremes. The continuous dis- 

 use of the muscles tends to their waste and 

 degeneration, to an impoverishment of the blood, 

 to a loss of tone of the nervous and other organs, 

 and to a gradual lowering of vitality. For ani- 

 mals that are soon to be sacrificed to the butcher, 

 this is not to be considered ; but for such as 



