44 STORRS AGRICULTURAL EXPERIMENT STATION, © 
Nutritive ratio.—There is a very important relation between 
the amounts of protein (flesh formers) and the amounts of fuel 
constituents of a food. ‘This relation is expressed by the nutritive 
ratio. The fuel value of fat is about two and one-fourth times 
that of the carbohydrates and the protein, hence it happens that 
if the sum of the digestible carbohydrates and two and one- 
fourth times the digestible fat of a ration is divided by the 
amount of digestible protein in the ration, the quotient gives 
what is called the nutritive ratio. 
Wide ration Narrow ration.—lf the quantities of digestible 
fat and carbohydrates are large relative to the protein, the nutri- 
tive ratio will be a large number and the ration is called a “‘ wide 
ration;” if the quantities of digestible fat and carbohydrates are | 
relatively small, the quotient is a small number and the ration is 
a “narrow” one. A ration where the nutritive ratio is much 
more than 1:6 may be called a ‘wide ration;” if much less it 
may be called a “narrow ration.” 
Nearly all of the grasses and hays have a large nutritive ratio, 
and the same is true of corn and many of its products, such as 
meal and hominy chops. The use of such feeding stuffs’ will 
tend to make a ration wide. ‘The legumes such as clover, peas, 
vetch, etc., and many of the products of milling and food manu- 
facture are relatively rich in protein, and hence have small nutri- 
tive ratios. Wide rations are much more common among American 
feeders than are narrow ones. Narrow rations would be better. 
Practically it is probably unwise to feed a ration whose nutritive 
ratio is greater than that of one to six or seven. 
The measure of the size of a ration.—In order that a ration may 
be complete, there must be enough digestible protein supplied in 
the food to build new tissues (bone, muscle, milk, etc.,) and repair 
the wastes of the body, and sufficient digestible fat and carbo- 
hydrates to furnish heat and muscular energy. As the chief 
function of the fat and carbohydrates is to serve as fuel, it is 
more important that enough of these should be provided to meet 
the needs of the animal than that they should be supplied in 
definite relative proportions. It is, therefore, possible to form a 
very good idea of the nutrients furnished in a ration, and to 
measure its size by the quantity of digestible protein or flesh- 
formers which it contains, and the fuel value of its digestible 
constituents. 
is 
a 

