190 BEEF PRODUCTION 



in all food-stuffs is small, it is absolutely necessary to 

 promote both animal and vegetable growth. As a matter 

 of fact, little attention has been paid to the ash constitu- 

 ents of plants intended for animal food, largely because 

 there has seemingly been a sufficient supply in most 

 food-stuffs. Recent investigations reveal the fact that 

 the ash constituents in food-stuffs are more closely re- 

 lated to commercial production of animal products than 

 was formerly supposed. 



Crude Protein, Fat, and Carbohydrates. — The organic 

 components of feeding-stuffs fall into three groups : 

 Crude protein, fats, and carbohydrates. 



Crude Protein. — The compounds of vegetable and ani- 

 mal structure containing nitrogen are in general terms 

 called crude protein. Compounds of this class vary 

 much in their nature, composition, and relative feeding 

 value. They have one thing in common, namely, the 

 possession of nitrogen. They are, therefore, frequently 

 spoken of as nitrogenous compounds. The most expen- 

 sive constituent in fertilizers is nitrogen; likewise the 

 most costly food-stuffs are those possessing the highest 

 percentage of digestible crude protein. Whatever other 

 functions protein may have, its chief one is that of a 

 flesh (lean meat) former. 



Carbohydrates. — The carbohydrates are divided into 

 two classes: crude fiber and nitrogen-free extract. The 

 crude fiber (composed principally of cellulose) is the 

 hard, woody framework of the plant. The portion avail- 

 able for nutrition is digested in the paunch and in 

 the intestines. Nitrogen-free extract includes the more 

 easily digested starches, sugars, and gums. The car- 

 bohydrates are the cheapest food-sources of heat, energy, 

 and fat. Since their function is the same as that of the 

 digestible fats found in feeding-stuffs, and since the fats 

 are about 2^ times as effective as the carbohydrates, it 

 is customary for the sake of simplicity to reckon them 



