CHAPTEE VIII. 



SUBSTITUTIONAL DIETING AND THE PRACTICE OF 

 SUBSTITUTION. 



Having fixed a ration suitable to the needs of any stud 

 of horses, it is not, as a rule, wise to make changes in 

 that ration for any but weighty reasons. Foodstuffs 

 vary in price, however, from time to time, and even a 

 slight fluctuation in the market price may mean a con- 

 siderable sum in the aggregate when a large number of 

 horses are being fed. Shortage of a foodstuff, or a bad 

 harvest in any particular country or district from which 

 a large part of the usual supply is obtained, may produce 

 such an increase in price that a change to some other 

 article of food is clearly indicated. Now for any substi- 

 tution to be wise, assuming the original ration to be a 

 sound one, it must conform to the following con- 

 ditions : 



1. The food substituted must be of the same nutritive 

 value in starch equivalent as that taken out of the 

 ration. 



2. The proper balance — especially the nitrogenous 

 ratio — of the ration must not be interfered with. 



3. The food substituted must be cheaper, in price of 

 its nutritive units, than the one in former use. 



It is because of the difficulty in meeting these required 

 conditions that substitution is not more commonly 



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