62 ELEMENTARY TREATISE ON STOCK FEEDS AND FEEDING 



large Calorie is equal to 1,000 small calories (written with a 

 small c). The Calorie is used more than calorie because of the 

 smaller figures necessary. Armsby of the Pennsylvania Experi- 

 ment Station, says : "For expressing the heat values of feeding 

 stuffs, it is convenient to use a unit one thousand times as large 

 as the Calorie, known as the therm, which accordingly is the 

 amount of heat required to raise the temperature of 1,000 kilo- 

 grams (2204.6 Ibs.) of water I degree Centigrade, or of 4,000 

 pounds of water i degree Fahrenheit. The heat value of corn 

 or any other fuel, as thus measured and expressed, would show 

 its value as fuel to be burned to make steam." 



These values are commonly called heats of combustion. 

 THE ENERGY VALUES OF SOME FEED STUFFS IN THERMS' 



Utilization of Energy. It is no doubt surprising to you that 

 wheat bran is not a great deal higher in chemical energy than 

 timothy hay; and corn meal than oat straw. Armsby says in 

 part: "Two causes combine to affect the utilization of the 

 chemical energy contained in feed stuffs. First, more or less 

 of the feed escapes from the body unburned. Much of even 

 the best feeding stuff escapes digestion and is excreted in the 

 dung, carrying with it a corresponding quantity of the chemi- 

 cal energy of the feed. More or less incompletely burned ma- 

 terial is also contained in the urine, while ruminants, and to a 

 certain extent horses, also give off combustible gases, arising 

 from fermentations in the digestive tract. Thus about 22 per 

 cent, of the chemical energy of corn meal and fully 55 per cent, 

 of that of average hay has been found to escape in these ways. 



1 Farmers' Bui. 346, U. S. D. A. 



