FEEDING EQUIPMENT 209 
The nutrients must first be reduced to the same value. The 
fat in a feed is richer than the others in heat value. Fat has been 
found to have an energy value of two and one-quarter times that 
of carbohydrates, so that it is necessary, in order to reduce them 
to the same value, to use this coefficient in the solution. Nutritive 
ratio can be expressed in the following manner, by formula: Given 
a ration containing 10 pounds protein, 30 pounds carbohydrates, 
and 5 pounds fat. 
Nutritive ratio=1: 4.13 
Protein : carbohydrates + (fat x2.25) 
10 : 30 + (5X2.25) 
10 : 41.25 
1 : 4.13 
It will be noticed in the above calculation that the amount of 
fat present was multiplied by 2.25. 
Potential Energy.—lIt is often helpful to know the heat values 
which the nutrients present in a ration will develop when consumed 
by the birds. This capacity is expressed by the term ‘ potential 
energy.” This means the measure of value in units of heat or 
energy in the nutrients themselves. 
Potential energy is expressed in calories per gram. A calory is 
a unit of heat or energy. It is used to mean the amount of heat 
necessary to raise one kilogram of water one degree of temperature 
on the centigrade thermometer. It is known that one gram of 
carbohydrates or of protein has a potential energy of 4.1 calories, 
while one gram of fat has a potential energy of 9.3 calories. In 
actual practice the energy value of any ration may be quickly 
determined by using the following multiples: One pound of pro- 
tein or of carbohydrates will develop 1,826 calories, and one pound 
of fat will develop 4,220 calories. 
Balanced Rations—A balanced ration is one which contains 
the nutrients in the proportion which meet the needs of the animal 
body for its best development and for the most economical pro- 
duction of the product desired. The rations may be expressed in 
a number of different ways. 
A ration which is high in carbohydrates and fat in proportion 
to the protein is said to be wide, and is balanced for the feeding 
for fat growth. A ration which has a nutritive ratio of about 
1 to 6 or 7 is said to be medium and is balanced for maintenance 
only. On the other hand, a nutritive ratio of 1 to 2 in which the 
protein very nearly equals the carbohydrates and fat is said to be 
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