12 The Bulletin. 



The protein compounds are of very great importance in feeds, for it 

 is from them that the animal derives the nitrogenous materials from 

 which its muscular tissues are built. 



FATS. 



Fats, or more properly termed ether extract, include all the substances 

 soluble in dry ether. These substances include the pure fats, such as 

 cotton-seed oil, linseed oil, etc., and the waxes, resins, chlorophyl, etc. 

 In most feeds the waxes and resins are present in such small amount 

 that the entire ether extract may be regarded as fat. In a few feeds, 

 such as alfalfa products, the ether extracts the chlorophyl or green color- 

 ing matter of the plants. This amounts to only a small per cent. 



CRUDE FIBER. 



The term crude fiber includes the woody parts or the structural 

 materials of plants. It is composed largely of cellulose and is the most 

 indigestible part of the feed. As a rule, a feed with a high percentage 

 of fiber is considered to be a low-grade feed. 



MOISTURE. 



Water is present to some extent in all classes of feed. Hays and com- 

 mercial feeds usually contain from 6 to 15 per cent of water. 



ASH. 



Ash is the inorganic or mineral matter of plants. It is composed 

 principally of soda, potash, lime and magnesia, combined in the form of 

 phosphates, sulphates, chlorides and carbonates. The constituents of 

 the ash furnish the material for the bony structure of animals and is 

 used only to a srnall extent in the tissues and organs. 



NITROGEN-FREE EXTRACT. 



The term nitrogen-free extract includes the non-nitrogenous constitu- 

 ents of feeds. The principal classes of substances included in this terra 

 are the sugars, starch, organic acids, pentosans,^ etc. In the ordinary 

 feed analysis the nitrogen-free extract is determined by difference; the 

 sum of the percentages of protein, fats, fiber, moisture and ash is sub- 

 tracted from 100, and the remainder considered as nitrogen-free extract. 



CARBOHYDRATES. 



The term carbohydrates includes the nitrogen-free extract and the 

 crude fiber. In publishing the analyses the nitrogen-free extract and 

 the crude fiber are reported separately. To get the per cent of carbo- 

 hydrates in a feed it is only necessary to add the percentages of these 

 two constituents. 



The percentage of carbohydrates as stated in the manufacturer's guar- 

 antee should be, as above stated, the sum of the per cent of nitrogen-free 

 extract and the per cent of crude fiber. 



