g N. H. AGE. EXPERIMENT STATION [Bulletin 169 



CRUDE FAT. 



The term crude fat is rather arbitrarily used to include 

 all the substances of the feed soluble in dry ether or simi- 

 lar solvents. They are the pure fats, such as cottonseed 

 oil, linseed oil, etc., and the waxes, resins, chlorophyl, etc. 

 These latter substances are generally so small in amount 

 that for practical purposes the ether extract of a feed 

 represents the amount of fat which it contains. The fats 

 are readily digested and rank next to protein in value. 



FIBRE. 



The crude fibre in a feeding-stuff is that portion which 

 goes to make up the cell-walls and structural material 

 of the plant. It is fairly indigestible and in general a 

 high percentage of crude fiibre indicates a low-grade feed. 



NITROGEN-FREE EXTRACT. 



The nitrogen-free extract is that portion of the feed 

 readily extracted by water or dilute acids and composed of 

 non-nitrogenous materials. The principal substances in- 

 cluded under the term are the starches and sugars. 



CARBOHYDRATES. 



The term carbohydrates is sometimes used in speaking of 

 feeding-stuffs. It is generally used to include both crude 

 fibre and nitrogen-free extract. A feeding-stuff which con- 

 tains small amounts of moisture, ash and crude fibre must 

 be classed as high grade, if digestible. When these con- 

 stituents are present in small amounts the total amount of 

 the valuable constituents — protein, fat and nitrogen-free 

 extract — must be high. 



