ABSTRACT
Foods are the main sources of nutrients and plant products form the bulk of diets of herbivores and ommivores. Water is an important constituent of most of the feeds and body, and it is essential for the survival and physiological functions of the body and should be counted with nutrients. The major constituents of common feeds are water, carbohydrates, proteins, lipids, minerals and vitamins. Higher concentration of soluble non starch polysaccharides is desirable in the diets of poultry due to following reasons: Proteins are the constitutional tissues responsible for the development of characteristic shape and size of body in conjunction with minerals. Amino acids are the units required for the synthesis of proteins. Some proteins are formed of derivatives of some normal amino acids or protein. Some examples of derived amino acids encountered in body and participate in specific physiological functions are presented in table.
