44 STORRS AGRICULTURAL EXPERIMENT STATION. 

Fuel value.—The value of food as fuel may be measured in terms of potential 
energy. The unit commonly used is the calorie. One calorie is the amount of 
heat necessary to raise the temperature of a pound of water about four degrees 
Fahrenheit.* From experiment it has been found that a pound of protein or 
carbohydrates yields, when burned, about 1,860 calories of fuel value, and that 
a pound of fat yields about 4,220 calories. 
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.—If the quantities of digestible fat and carbo- 
hydrates are large relative to the protein, the nutritive ratio will be a large 
number and the ration is called a ’ if the quantities of digestible 
fat and carbohydrates are relatively small, the quotient is a small number and 
’ 
‘narrow’’ one. A ration where the nutritive ratio is much more 
6 
‘wide ration;’ 
6 
the ration is a 
6s 
than 1:6 may be called a ‘‘ wide ration;’”’ if much less, it may be called a “‘ nar- 
row ration.”’ 
Nearly all of the grasses and hays have a wide 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 narrow nutritive ratios. 
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 carbohydrates to furnish heat and muscular energy. As the 
chief function of the fat and carbohydrates is to serve as fuel, it is more import- 
ant 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, there- 
fore, 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. 
RESULTS OF THE HXPERIMENTS, 
Tables 1 to 8 inclusive contain in considerable detail the 
results of the observations and studies of the different herds. 
The following abbreviations are used in the tables: 
Abbreviations Used in Report of Rations Fed to Milch Cows. 
Ay.=Ayrshire. Gy.=Guernsey. P. == Pure Breed 
Dev. = Devon. Hol. = Holstein. R.—Registered. 
Dur.= Durham. We) ersey, Sw.—=Swiss. 
Gr Grade: Nat. = Native. 
* The Calorie is exactly the heat necessary to raise the temperature of one kilogram of 
water one degree Centigrade. It is equivalent to 1.5 foot tons, or to the mechanical power 
that would lift 1.5 tons one foot. 
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