CHAPTER XXIV 



FEEDING WORKING ANIMALS 



THE working animals now in use in the United 

 States are chiefly horses and mules. Oxen were once 

 employed extensively for farm labor and in lumbering, 

 but these are rarely seen under the yoke at the pres- 

 ent time, except in remote rural districts. It will be 

 proper, therefore, to treat in this connection chiefly of 

 horses that are used for draft and road purposes. 



The horse a machine. In feeding a working animal 

 the essential product of the food is energy to be used 

 in drawing, walking or trotting. The latent food en- 

 ergy is made available, as heretofore stated, by the 

 oxidation of the several nutrients into the ordinary 

 products of combustion, and the units of heat or work 

 or other forms of kinetic energy evolved are directly 

 proportional to the quantity of digested food which 

 suffers combustion, just as the possible work of a 

 steam engine under given conditions is proportional 

 to the fuel consumption in the boiler. The establish- 

 ment of fundamental relations between food and work 

 requires on the one hand an understanding of the 

 energy values of food, and on the other hand at least 

 a general conception of the amount of work performed. 

 The energy values of food have been considered and 



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