58 THE ECONOMICS OF FEEDING HORSES 



ingredient are also calculated and added together. Then 

 the ratio is obtained by comparing the total protein 

 with the sum of the total fats (in terms of starch) and 

 carbo-hydrates, including digestible fibre. Expressed as 

 a formula this is — 



N 



FX2-3+C.-H.4-D.F. 



The nitrogenous ratios of the food supplied to horses 

 under different conditions of age and work must be 

 varied if optimum results are desired. 



In the foal, with his great need of protein material 

 for growing muscle and other nitrogenous tissues, the 

 natural food — milk — has a nitrogenous ratio of 1:3. 

 This is narrower, or, in other words, represents a higher 

 proportion of protein to other nutrients than is necessary 

 or even suitable under any conditions of work. 



Fop work the narrowest ratio required is 1 : 5"5 or 

 1 : 6, and this is desirable when the work is severe, and 

 especially if it has to be done at a high speed. The 

 thoroughbred, the hunter, and the fast harness-horse, 

 need this high proportion of protein, and, similarly, 

 though perhaps to a less extent, the heavy van-horse 

 worked at a trot, as in London, and even the heavy 

 dray-horse, where the hours are long, the work hard, 

 and severe calls are made frequently upon the animal's 

 strength in starting heavy loads. For slower work, such 

 as that of the farm, or where the working hours are 

 short, and only moderate exertion is called for, a ratio 

 of 1 : 8 is quite sufficient. For resting horses in good 

 condition the maintenance ratio of 1 : 10 answers all 

 requirements (see p. 46). The calculation of the 

 '* nitrogenous ratio " of a complete ration is shown in 

 the examples on p. 76. 



