38 THE ECONOMICS OF FEEDING HORSES 



different animals, and for different purposes in the 

 same animal, but any other than the optimum nutritve 

 ratio is attended with waste of one or other of the 

 constituents supplied, and is bound to be uneconomical. 

 If this optimum balance is upset, the percentage of each 

 food digested at once alters — e.g., if the percentage of 

 protein in a ration is too low, the digestion of protein 

 per 100 parts supplied in the food falls off, and so the 

 nitrogenous part of the diet, the most costly part, is 

 subject to greater waste. Again, if the quantity of 

 protein supplied is excessive, the appetite for it increases, 

 the animal puts on flesh, and extravagance occurs. To 

 determine the right proportion in which to supply these 

 nutritive elements in food, we may proceed in two ways : 

 (1) by studying this proportion in the natural food of 

 the animal we are considering, and by noting how the 

 ratio varies with the varying circumstances of the 

 animal's life ; and (2) by experimentally determining 

 the best balance for any particular animal used for a 

 particular purpose. Since the performing of work is 

 unnatural, we can get little or no information from 

 Nature at all comparable with working conditions, so that 

 the latter method is the better for working rations. In the 

 feeding of young animals — foals and calves — we can 

 use the former method with great advantage by 

 analysing their natural food — namely, milk. 



The ratios which we require to know are termed the 

 '' nitrogrenous " and the "fatty" ratios, the former 

 being by far the more important. They may be repre- 

 sented thus : 



N 



Nitrogenous ratio = 



Fx2-3-l-C.-H. + D.F. 



■pi 

 Fatty ratio = — 



