246 



Agricultural Chemistry. 



ance of therms is provided in addition to the maintenance ration, 

 no additional protein is required for fattening purposes. On the 

 other hand, for milk production the standard provides additional 

 protein. This must be done because of the protein content of 

 the milk itself and the additional factor of protein supply for 

 the developing foetus. 



3. Armsby recommends that a 1000 pound ruminant should 

 be given from 20 to 30 pounds of dry matter per day, while for 

 the horse smaller amounts can be used. 



Standard for the working animal. The horse is the only ani- 

 mal to be considered here. What applies to the horse may also 

 be used for the mule. As a general average, Kellner recommends 

 the following ration for a 1000 pound horse, the amounts stated 

 including the maintenance requirement: 



Requirements of the Working Horse. 



Future of standards. The feeding standards being developed 

 at the present time are in a formative stage, and necessarily in- 

 complete. No standard should be used as an exact mathematical 

 expression of the animal 's needs. In fact it cannot be done, be- 

 cause we are not in a position to know the exact requirements of 

 the individual animal; again, feeding stuffs of the same namt 

 show a considerable range in composition. Further, probably th( 

 most important factor in limiting the adoption of a feeding 

 standard as a final recipe in feeding, is the difference in nutritive 

 value and physiological action of the nutrients from varioi 

 sources. One species of farm animal may do better on the nu- 

 trients from one specific source, as compared with those derived 



