DEFINITIONS OF TERMS USED. 243 



pound of grain (corn, barley, wheat or rye). For list of feed units, 

 see page 219. 



Feeding standard. A numerical expression of the amount of 

 various digestible substances in a combination of feeding stuffs 

 best adapted to give good results as regards production of animal 

 products, like beef, pork, milk, etc. 



Fiber. The frame work forming the walls of cells of plants. 

 It is composed of cellulose and lignin, the latter being the woody 

 portion of plants and wholly indigestible. 



Glucose or fruit sugar. The form of sugar found in fruits, 

 honey, etc., also in the alimentary canal. 



Indian corn. Zea mays, the great American cereal and fodder- 

 producing plant. 



Hydrogen. A chemical element, a gas. Combined with oxygen 

 it forms water, with oxygen and carbon it forms carbohydrates 

 and fat; with oxygen, carbon and nitrogen (with small amounts 

 of sulphur and phosphorus) it forms the complex organic nitro- 

 genous substances known as protein or albuminoid substances. 



Legumes. Plants bearing seeds in pods and indirectly capable 

 of fixing the free nitrogen of the air, so that it becomes of value 

 to the farmer and will supply nitrogenous food substances to 

 farm animals. Examples, the different kinds of clover, alfalfa, 

 peas, beans, vetches, etc. Of the highest importance agriculturally 

 as soil renovators, and in supplying farm -grown protein foods. 



Maintenance ration. An allowance of feed sufficient to main- 

 tain a resting animal in body weight so that it will neither gain 

 nor lose weight. 



Nitrogen. A chemical element, making up four-fifths of the 

 air. The central element of protein. See under hydrogen. 



Nitrogen -free extract. The portion of a feeding stuff remain- 

 ing when water, fat, protein, fiber, and ash are deducted. It in- 

 cludes starch, sugar, pentosans, and other substances. It is so 

 called because it does not contain any nitrogen. 



Nitrogenous substances. Substances containing nitrogen 

 (which see). 



Nutrient. A food constituent or group of food constituents 

 capable of nourishing animals. 



