134 SWINE 



of all feeds. Those classified as dry feeds contain a com- 

 paratively small per cent of water, ranging from 8 to 18 

 per cent, while the succulent feeds, such as grass and 

 roots, may contain as high as 85 to 90 per cent of water. 

 The liquid feeds such as skim milk and buttermilk also 

 contain a large per cent of water from 85 to 90. In or- 

 der that a hog may develop properly, he must have a suf- 

 ficient amount of water. If this is not present in suffi- 

 cient quantities' in the feeds used in the ration, and it 

 usually is not except in the liquid feeds and roots, it must 

 be supplied as such. 



AIR. 



Aside from the dry feeds and from water, there is a 

 third source from which the building material for the 

 animal body is obtained. This is the oxygen from the air. 

 While great stress has been laid upon dry feeds, and a 

 great amount of experimental work has been done to de- 

 termine the value of dry feeds of different kinds, very 

 little has been done to determine the value of water, and 

 nothing has been done as regards the value of air in the 

 nutrition of the animal body, although pure air has al- 

 ways been considered essential for the health of the ani- 

 mal. Nevertheless, it is known that an animal can live 

 for weeks without any dry feeds; it can live for several 

 days without any water ; but it cannot live for more than 

 a few minutes without air. From this it would seem 

 that these sources of food supply have been considered in 

 reverse order. If an animal can live but a few minutes 

 without air, or a supply of oxygen, should not this point 

 be given primary consideration? And if it can live but a 

 comparatively short time without water, this should also 

 be given more consideration than has been done in the 

 past. 



