THE CHEMICAL COMPOSITION OF FEEDINGSTUFFS 9 



As a rule, the cereal grains, silage, and roots, are quite low 

 in ash, — 1 to 3 per cent. 



CRUDE PROTEIN 



Crude protein includes all the substances of the plant 

 or animal which contain the element nitrogen. In general, 

 crude protein consists of two sub-classes of substances : 

 (1) proteins, often called true protein, and (2) non-proteins, 

 which is an abbreviation for '' non-protein nitrogen-contain- 

 ing substances." 



Proteins. — In every living organism there are present 

 highly complex, nitrogen-containing compounds to which 

 the general name proteins has been given. These sub- 

 stances form the chief part of the solid matter of the blood, 

 muscles, nerves, glands, and organs of the animal, and 

 occur in smaller amounts in every part of plants, but es- 

 pecially in the seeds. They form an essential part of the 

 protoplasm of every cell, plant or animal. They also are 

 important constituents of the cell wall of all animal cells, 

 and are always present in the fluids which surround the 

 cell. As a nutrient, the proteins occupy an important 

 position, due to the fact that they are the only nutrient 

 which contains nitrogen in forms available to the animal 

 body. Thus, they are necessary not only for the growth 

 and development, but also for the life, of every animal. 

 Water, mineral matter, and protein are absolutely essential 

 constituents of the rations of all animals. An animal soon 

 dies if water, mineral matter, or protein is withheld from 

 the ration. If an insufficient amount of any of these nu- 

 trients is given, the animal fails to develop properly, and 

 in extreme cases dies. 



