Aug., 1922] inspection of feeding stuffs 5 



practical purposes it is sufficiently accurate. Protein, then, 

 is made up of the compounds in the feed which contain 

 nitrogen. 



Fat is determined by extracting a dried sample of the 

 feeding-stuff 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 the leaves), waxes, resins, 

 etc. ; but for practical purposes it is accurate enough to deal 

 with it as fat. 



Ash is determined by weighing the residue after the feed- 

 ing-stuff has been burned at a low temperature. It con- 

 tains the mineral matter of feeding-stuffs. 



Moisture is determined by finding the loss in weight after 

 heating at the temperature of boiling water. It shows the 

 amount of water that the feed contains. 



Carbohydrates are determined by adding the percentages 

 of the protein, fat, moisture and ash, and subtracting the 

 total from 100 per cent. The carbohydrates 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 fiber is called 

 nitrogeyi free extract. 



Crude Fiber is made up of the more woody-like carbohy- 

 drates which are largely of a cellulose nature. Pure cotton 

 is an example of almost pure cellulose. Wood, straw, corn 

 fodder, etc., are materials 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 



