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 + (f at X 2.25) 

 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. It 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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