ANIMAL HUSBANDRY 



CHAPTER I 

 THE COMPOSITION OF THE ANIMAL BODY 



In feeding animals, the feeder may consider himself a 

 builder who uses feeds as materials with which to build 

 the animal body. But the animal itself should be regarded 

 as something more than a building. It may also be con- 

 sidered as a machine which, while being operated and 

 kept in running order, creates heat, performs work, repairs 

 broken-down material, builds new material, and grows and 

 reproduces itself. 



The plant and the animal bodies are built up from 

 various substances which perform distinct functions and 

 make up different parts of the organisms. The chemist 

 has found about 13 chemical elements essential to plants. 

 They are carbon, hydrogen, oxygen, nitrogen, sulphur, 

 phosphorus, potassium, calcium, magnesium, iron, sodium, 

 sihcon, and chlorine. These elements combine to form the 

 following substances in both plant and animal life : 



1. Proteins, 4. Mineral substances, 



2. Carbohydrates, 5. Water. 



3. Fats, 



Proteins. — These substances contain carbon, hydrogen; 

 oxygen, nitrogen, and usually sulphur and phosphorus. 



