40 



THE ECONOMICS OF FEEDING HORSES 



X 2*3 we arrive at a total representing the comparative 

 heat value of the food in terms of digestible starch.* 



The correction for crude fibre must still be made,t so 

 that if the percentage of this in the food under examina- 

 tion is 12, we have to deduct -V"- = 4 from the total 

 representing the comparative heat value. The corrected 

 total now represents the real value of 100 lbs. of the 

 food, and is called the " starch equivalent " of the food. 

 Arrived at in this way, it affords the most practicable 

 means of stating the relative nutritive value of any food- 

 stuff. 



Two examples will suffice to make the estimation of 

 the nutritive value of a food quite plain. Oats and hay 

 have been selected as being the commonest foodstuffs 

 supplied to horses. 



I. Oats. 



* For 1 lb. of proteid matter and 1 lb. of carbo-hydrate (starch) 

 are of the same value, and 1 lb. of fat is equivalent to 2*3 lbs. of 

 carbo-hydrate (starch), so that 1 lb. protein + 1 lb. carbo-hydrate 

 + 1 lb. fat = 4-3 lbs. starch. 



t See p. 36. 



X Since oats contain 10 per cent, of crude fibre. 



