Aug., 1921] inspection of feeding stuffs 5 



Fat is determined by extracting a dried sample of the feedstuff 

 with ether and weighing the residue after the ether is driven off. 

 In main it contains the vegetable fats of which olive oil, linseed 

 oil, peanut oil, and cottonseed oil are examples. It contains also 

 small amounts of chlorophyll (the green coloring matter of 

 leaves), waxes, resins, etc.; but for practical purposes it is accur- 

 ate enough to deal with it as fat. 



Ash is determined by weighing the residue after the feedstuff has 

 been burned at a low temperature. It contains the mineral matter 

 of feedstuffs. 



Moisture is determined by finding the loss in weight after heat- 

 ing at the temperature of boiling water. It shows the amount of 

 water that the feed contains. 



Carbohydrates are determined by adding the percentage of pro- 

 tein, fat, moisture, and ash and subtracting it from 100. The car- 

 bohydrates are composed largely of starches, sugars, pentosans, 

 celluloses, etc. The carbohydrates include the crude fiber also. The 

 percentage of carbohydrates less the percentage of crude fibre is 

 called nitrogen free extract. 



Crude Fibre is made up of the more woody-like carbohydrates, 

 which are largely of cellulose nature. Pure cotton is an example of 

 almost pure cellulose. Wood, straw, corn fodder, etc., are materi- 

 als which are high in crude fiber content. 



WHAT ARE FOODS FOR ANIMALS? 



In order that an animal may continue to live even without 

 making growth or producing wool, eggs, milk, or work, etc., there 

 are certain food materials which it must have. The animal must 

 have a certain amount of protein, fat, carbohydrates, water and 

 mineral constituents. In addition there are other things, known 

 as "vitamines," "growth promoting substances," or "food acces- 

 sories," the chemical nature of which is not well understood, which 



