FEEDS 409 



the volatilization of these ions. The ash of feeds contains the basic 

 elements as oxides, carbonates, and phosphates, although these com- 

 poiuids may not have existed as such in the feed. Therefore, the ash 

 determination is only a rough index of the true mineral content of 

 the feed. 



Carbohydrate (Nitrogen-free Extract) 



The percentages of crude protein, crude fat, crude fiber, and ash 

 on a moisture-free basis are totaled and subtracted from 100. This 

 difference is the so-called "nitrogen-free extract" (N.F.E.), which is 

 composed almost entirely of carbohydrates, although small amounts 

 of certain organic acids and similar materials are included. For prac- 

 tical feeding purposes nitrogen-free extract may be considered synony- 

 mous with carbohydrates. 



Regulation and Control of Composition 



The Federal Food and Drug Act of 1906, revised in 1938, was en- 

 acted to protect the American public by regulating the manufacture 

 and sale of foods, feeds, and drugs sold in interstate commerce. Stand- 

 ards for each type of commodity were established by law. Today most 

 of the states in the United States also have enacted food laws con- 

 trolling the purity and quality of foods and feeds manufactured or 

 sold within their respective borders. 



So far as laws relative to commercial feeds are concerned, all of 

 them express feed composition in terms of moisture, crude protein, 

 crude fat (ether extract), crude fibers, ash, and nitrogen-free extract, 

 as described above. In order that the feed buyer may be protected, 

 most feeding-stuff laws require that the manufacturer submit a guar- 

 antee regarding the chemical composition of the feed. If the feed- 

 inspection laboratories find that a product does not conform to the 

 guaranteed analysis, the manufacturer and the dealer are subject to 

 legal action. 



Many animal feeds differ in chemical composition from those foods 

 commonly used for human consiunption. This is due to the fact that 

 domestic animals are capable of utilizing many products that the hu- 

 man digestive tract cannot. 



FEEDS OF PLANT ORIGIN 



Feeding stuffs may be classified from the standpoint of source of 

 material, beginning with the feeds obtained from plant sources. 



