This method makes the determination possible of free (synthetic and natural) and total (peptide bound and free) amino acids in feed, using an amino acid analyser. It is applicable to the following amino acids: cyst(e)ine, methionine, lysine, threonine, alanine, arginine, aspartic acid, glutamic acid, glycine, histidine, isoleucine, leucine, phenylalanine, proline, serine, tyrosine and valine.
Adults require nine essential amino acids ... Infants and growing children require 10 amino acids, the extra one being arginine. Although arginine is normally made by the liver as a step in the synthesis of urea, children cannot make arginine fast enough to support both urea synthesis and the synthesis of body proteins.