128 SWINE 



Fat or Ether Extract. — The nutrient known as fat, or 

 ether extract, is found to a greater or less extent in all 

 feeds. These compounds are used by the animal body 

 for the same ultimate purpose as the carbohydrate nu- 

 trients. The term ether extract is usually used instead 

 of fat because ether is used in extracting the fat from the 

 feed stuff when determining how much it contains. The 

 extract when thus obtained has other materials in it such 

 as wax, chlorophyll, etc., and is not pure fat ; consequently 

 is called ether extract. 



Mineral Matter. — The mineral nutrients are such sub- 

 stances as common salt, lime, potash, the phosphates, etc, 

 These are necessary for the construction of bone as well 

 as for the proper working of the other functions of the 

 animal body. All feeds contain some mineral matter ; 

 some feeds contain a considerable quantity, others a very 

 small quantity. Different soils contain varying quanti- 

 ties of mineral matter, and vegetation grown on these 

 soils will have varying quantities of mineral matter con- 

 tained in it in accordance with the soil upon which it. 

 grows. Ground water also contains more or less mineral 

 matter in accordance with the quantities in the soil. 



DRY FEEDS 



Feeds in general, such as corn, rye, oats, barley, skim 

 milk, grass, roots, etc., are usually considered as the pri- 

 mary sources of the necessary building material for the 

 hog, as well as for other animals. Some feeds, such as 

 corn, rye, barley, etc., are made up largely of carbohydrate 

 material and are called carbonaceous feeds. Besides con- 

 taining carbohydrate they also contain some of the other 

 food nutrients, such as protein, ether extract or fat, and 

 mineral matter; also some water. It is very fortunate 



