SECTION LIX. PRINCIPLES OF FEEDING 

 ANIMALS 



ANIMALS cannot feed on the minerals in the soil nor 

 on the carbon dioxid in the air. The plant lives upon 

 both. The chief use of the plant to man is in chang- 

 ing the minerals from the soil and the carbon dioxid from 

 the air into substances fit to nourish man and his servants, 

 the domestic animals. Plants form the natural food of the 

 animals of the farm. 



The same classes of substances are found in the bodies 

 of plants and animals. These are water, ash, and protein 

 (that is, materials containing nitrogen). Each of these sub- 

 stances in the plant goes to form somewhat similar matter 

 in the animal body. But plants contain substances not 

 found in the flesh of animals ; these are starch and sugar. 

 Yet starch and sugar are among the most important foods 

 of animals. Instead of adding these to its own body un- 

 changed, the animal converts starch and sugar into animal 

 fat, or uses them as fuel. 



Ash. This is the part of the dry matter of plants or 

 animals that will not burn. There is generally an abun- 

 dance of ash in the common foods to supply all that animals 

 need. But pigs fed on corn alone without any pasturage 

 may be helped by giving them wood ashes, which aid in 

 the formation of their bones and in other ways. Fowls 



3'4 



