270 BEGINNINGS IN ANIMAL HUSBANDRY 



oats highly for producing hard, strong bone in growing 

 animals. 



All food has a heat value, just as coal has. If burned, 

 coal gives off heat; so does food. All heat comes from the 

 sun, and is stored up in the plant, ready to be set free. 

 The word calorie represents a measure of heat given off by 

 food. One calorie equals the amount of heat required 

 to raise the temperature of 1 pound of water 4 F. The 

 word therm is now being adopted as more convenient for use 

 in referring to stock feeding. A therm equals 1000 calories. 

 If we raise 1000 pounds of water 4 F, that measures a therm. 

 While food is being digested in the body, heat is produced 

 by the process. Some foods contain more heat than others. 

 The difference will depend largely on the amount of fat con- 

 tained. Scientific men consider that the heat values of pro- 

 tein and carbohydrates are about alike, but that the heat 

 value of fat is 2% times as great as either of these. This 

 partly explains why the Eskimos in the cold north eat so much 

 food that is nearly all fat, as the blubber of the whale. 

 Corn contains more fat that any of our common grains, 

 which accounts in part for its use as a winter feed for 

 horses, and also is a reason why it should not be fed heavily 

 to stock in summer in the warm season. 



Food has an energy value. When a substance is burned, 

 the resulting energy furnishes power to do work. So it is 

 Understood that what we call a therm represents the energy 

 or work necessary to raise 1530 tons to a height of one foot. 

 Part of the energy of the food, to be sure, is lost in the process 

 of digestion, partly because not all the food is digested. But 

 much of it is saved, and this is used to keep the engine of the 

 body going. The horse that pulls the plow or hauls a load 

 of hay gets his power from the stored-up energy in the 

 food, which is set free in the body during oxidation. 



