56 FARM ANIMALS 
heat and energy. The fat, now having been reduced to a 
carbohydrate basis, can be added to 66.8, the amount of 
carbohydrates in corn, which gives 76.7 pounds of total 
carbohydrates. This sum, divided by the number repre- 
senting the quantity of protein, which in the case of corn 
is 7.8 pounds, gives the final factor of the ratio, or 9.8. 
In the form of proportion the stages are as follows: 
(1) The amount of protein is to the amount of the carbohydrates 
as 1 is to the factor to be determined. 
(2) Protein : Carbohydrates ::1: x. 
(3) 78: (668499) ::1: x. 
(4) 78 76.7 ::1 98. 
The nutritive ratio of corn is therefore 1 to 9.8, which means that 
in this feeding stuff for every pound of digestible protein there are 
9.8 pounds of digestible carbohydrates and fat equivalent. 
5. Wide or narrow nutritive ratio—-A wide difference 
exists among feeds as to the amount of protein. The oil 
meals and the legumes are rich in protein, roots and straw 
very poor, while cereal grain and their products occupy a 
middle place. These differences give rise to the terms 
wide and narrow nutritive ratios, which apply to both sin- 
gle feeds and rations. A feed or a ration has a “narrow” 
nutritive ratio when the digestible protein it contains is 
high in comparison to the carbohydrates and fat, and 
“wide” when the reverse. 
6. Balanced ration.—Since all feeding stuffs, with the 
possible exception of pasture grass, are unfit as single 
food substances, they naturally fall into a class as being 
either wide or narrow. If two or more are combined in 
the proper proportions to furnish all the digestible nutri- 
ents, with no excess or shortage of any nutrient, but in 
just the quantity needed by a certain class of animals fed 
for a distinct purpose, the combination is then satisfac- 
tory, and does provide a balanced ration. 
7. Feeding standards—For many years investigators 
have been conducting feeding tests to learn the amount 
