THE RATIONAL FEEDING OF DAIRY STOCK 135 



serve for the production of fat in the body. The 

 carbohydrates from different food stuffs vary widely 

 in character. In the potato, starch is the main carbo- 

 hydrate ; in beets, it is sugar ; in apples, pectose or 

 jellylike substances; and in hay and coarse fodders, 

 pentosans predominate, or bodies that can be con- 

 verted into sugarlike substances containing five 

 atoms of carbon in the molecule. 



129 . Crude Fiber . — The term " crude fiber " is applied 

 to the cellular tissues of which the framework of 

 plants is composed. A jjortion of the fiber is digest- 

 ible and capable of serving the same functions us the 

 soluble carbohydrates. Foods with excessive amounts 

 of fiber are objectionable, but on the other hand some 

 fiber is desirable in order to give the necessary bulk 

 to a ration. 



130. Crude Fat. ■ — All food stuffs contain some 

 fatty compounds. In farm grains from 2 to 5 per 

 cent of ether extract or crude fat is present ; in coarse 

 fodders from lo to 2.25 per cent; while in some of 

 the specially prepared mill products, as oil meal, 10 

 per cent or more of fat may be present. The fat 

 in food stuffs is extracted with ether, and hence the 

 term "ether extract" is used. In addition to the fats, 

 ether extract contains small amounts of other sub- 

 stances, as chlorophyll and resin. Hence the ether 

 extract is not pure fat. From grains and mill prod- 

 ucts, however, the ether extract is nearly pure fat, 

 wliile in that from coarse fodders there is only from 

 50 to 75 per cent of pure fat. Fats are character- 



