Til 10 HULI-KTIN. 11 



ASH. 



Ash is the iiioi-ganic or mineral matter of plants. It is composed 

 principally of soda, ])n(asli, 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 small 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 term 

 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. 



The following classification will give a clearer understanding of the 

 facts presented above: 



T^ ■ • /-ivT /. OKN ( True proteins. 

 Protein (N x 6.25) i a •/ ;, 



^ ^ { Amido compounds. 



-r^ /-r-i 1 -n , ^ ( Truo fats. 



I'atS (Jither JliXtract) i -nr • . •^ ^^ 11^ 



^ ^ ( Waxes, resins, organic acids, chlorophyl, etc. 



„ , , , f Nitrogen-free extract. I ^x i ' 



Carbohydrates | p j o^ \ starch, 



^ ' t Pentosans, etc. 



MICROSCOPIC ANALYSIS OF FEEDS. 



In addition to the regular chemical analysis, all the feed samples are 

 examined microscopically. This is the final test of their purity. 



The chemical analysis shows the percentage amounts of the nutritive 

 constituents of the feed, but it gives no idea of the source from which 

 they are derived, and as the protein and fat are more digestible and 

 hence more valuable in some classes of feeds than in others, it is very 

 important to know just what substances go to make up the feed. The 

 microscopic examination is the only way this can be done with any 

 degree of accuracy. 



The chief use of the microscope in feed analysis is in the detection of 

 adulterants and in the detection of the use of spoiled or low-grade seeds. 

 Many feeds are now" put on the market in finely ground condition, and 



