6 N. H. EXPERIMENT STATION [Bulletin 213 



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 cr-ude 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 other things known as "vita- 

 mines", "growth promoting substances" or "food accessories", 

 the chemical nature of which we know very little, are necessary. 

 The latter substances, however, are usually present in sufficient 

 quantities in our regular feeding-stuffs if we feed a sufficient va- 

 riety and particularly if we feed a good legumiinous roughage. 

 Our feeding-stuffs usually contain mineral matter sufficient for 

 the needs of an animal with a few exceptions, such as calcium 

 carbonate, which we furnish as oyster shells for hens and phos- 

 phorus and calcium which is sometimes fed to dairy cattle and 

 pigs in the form of bone meal. If alfalfa or clover is fed as a 

 roughage they will aid very much in furnishing a proper mineral 

 supply. The protein, fat and carbohydrates arc the foods which 

 we are particidarly interested in when we buy commercial feed- 

 ing-stuffs and it is their content which largely determines the 

 value of the feed. 



DIGESTIBILITY IMPORTANT IN DETERMINING THE 



VALUE OF FEED 



When fed, not all of the protein, carbohydrates, and fat in 

 the different feeding-stuffs are digested. In comparing the value 

 of the different types, we must take into consideration the digest- 

 ibility of these food nutrients. The coefficient of digestibility is 

 a term which expresses the percentage amount of the food nutri- 

 ents which are digested and absorbed by the animal. Table No 

 3 gives a summary of the average results for some of our 

 common feeding-stuffs. 



