228 THE CHEMISTRY OF CATTLE FEEDING 



method of computing the number of food-units and (;/) the 

 price per unit in a meal sold at $ los. per ton (= nos.) : 



Nutrients. Per cent. Factor. Food-units. 



Crude protein ... 12*5 x 2'5 = 3 I>2 5 



Crude fat .... 6'6 x 2*5 = 16*50 



Soluble carbohydrates 57-9 X ro = 57'Qo 



Total. .... 105-65 



n = no -^ 105-65 = 1-04 shillings. 



The following examples show the variation in the price 

 per unit in some of the common feeding stuffs : 



The term " food-units " is a misnomer. If it has any mean- 

 ing at all it refers to the pecuniary, not the nutritive or " food " 

 value of the substances. Feeding stuffs are, however, often 

 compared on the basis of the number of food-units they 

 contain, but such comparisons are not reliable. The nutritive 

 value of i Ib. of protein is not equal to that of 2\ Ibs. of 

 carbohydrates. So far as it performs similar functions it is 

 probably not quite equal to i Ib. of carbohydrate. When it 

 performs different functions, as it should and usually does, 

 there can be no comparison of nutritive values on any basis 

 whatever. 



For purely commercial purposes, however, if the number 

 of food-units be accepted as the basis of pecuniary value, it 

 can be used to advantage in several ways : 



(i) If the price per ton and composition of any feeding 

 stuff be known, the price per unit can be determined. 



