Cells in the pigeon's body are made up mainly of proteins, die off regularly, and must be replenished. Proteins are built up from combination of three or more amino acids,There are about 24 different kind of amino acids, There are about 24 different kinds of amino acids,but they are not all contained in a single protein.Three or more combinations of amino acids are contained in various legumes,cereals and seeds. For example, a garden pea contains an amino acid combinations of 1,8 and 17, and wheat a combination of 6,10 and 21.A large amount of protein is obtained from legumes about 16-2 percent, and from cereals about 11 percent Because the amino acid compositions are different in the various legumes and cereals, a mix must be provided to ensure a balanced diet. Proteins fulfill several important functions: