240 MAiq-UAL OF CATTLE-FEEBIKG-. 



stance of the animal, which would otherwise be burned in 

 warming the food, is rendered available for other purposes. 

 This fact, in connection with the increased palatabilitj^ of 

 the fodder and the consequently greater consumption of 

 it, probably explains the favorable results frequently ob- 

 tained by means of this practice, and at the same time 

 renders it evident that its profitableness must depend on 

 circumstances. Under some conditions, the gain thus 

 effected might repay the expense, while under other con- 

 ditions it might be more economical to let the cattle warm 

 their own food. 



Production of Chemioal OirANGES.-The food being, 

 as already explained, the means by which supplies of force 

 are introduced into the body, it is evident that any change 

 taking place in the constituents of the food before they 

 become part of the body by which any of the force which 

 they contain is liberated, involves an equivalent loss to 

 the organism. It is as if the fuel which is to drive the 

 engine were partially burned before being put under the 

 boiler. 



Such elianges actually take place in the food to some ex- 

 tent during digestion. For example, we have all along 

 assumed that the carbhydrates yield grape-sugar in the 

 alimentary canal, and all calculations of rations are based 

 on that assumption. In the main it is probably correct ; 

 but it is known that portions of these bodies suffer still 

 further decomposition and yield lactic acid. In this pro- 

 cess some of the latent force of the carbhydrates appears 

 as heat, and the resulting lactic acid and other products 

 are less valuable to the body by just the amount of force 

 thus liberated. 



It was stated on page 64, that many good authorities con- 

 sider that the digestion of cellulose consists essentially in 



