FEEDS AND FEEDING I45 



substances, which are nitrogenous compounds or pro- 

 tein. 



Fat or oil, the materials dissolved from a feeding 

 stuff by ether, is an impure product and includes 

 besides real fats, wax, the green coloring matter of 

 plants, etc. The fat of food is either stored up in the 

 body as fat or used to furnish heat or energy. One 

 pound of fat will produce as much heat as two and 

 •one-quarter pounds of carbohydrates. 



Organic matter includes all that portion of a feed- 

 ing stuff that may be burned off, and hence includes 

 ■everything except the water and ash. The fuel value 

 is expressed in a term or unit named the "calorie." 

 The calorie is the amount of heat required to raise the 

 temperature of one kilogram of water one degree 

 ■centigrade (one pound water, .818 degree Fahrenheit). 

 From practical experiment it has been found that a 

 pound of protein or of carbohydrates yields, when 

 ^burned, about i860 calories of potential energy, and 

 that a pound of fat yields 4^0 calories, or over twice 

 as much. The total number of calories in the digestible 

 matter in 100 pounds of feed is a measure of its heat- 

 ing effect, or fuel value, or, potential energy. High 

 •potential energy shows a concentrated food. 



Nutritive ratio is the relation between the protein 

 an a food and the fat and carbohydrates. To ascertain 

 it, multiply the fat by two and one-quarter to equal the 

 •carbohydrates, add the latter and divide the total by 

 the amount of protein. Foods with a large proportion 

 •of carbohydrates are wide in ratio. A common exam- 

 ple is corn. Foods with the proportion of carbohy- 

 •drates smaller in proportion to the protein are narrow 

 ratio, as in the case of bran or meat scrap. Food with 

 narrow ratio are generally highly concentrated and 

 tend to produce eggs and rapid growth. Foods or 

 mixtures of wide ratio are more heating and fattening. 



