The Importance of Dispensable Amino Acids for Maximal Growth in the Rat

Various quantities of dispensable amino acids have been fed to rats in an attempt to determine what combination is best for maximal growth. The quantity of one dispensable amino acid that was necessary for maximal growth has been shown to depend upon the quantity of one or more other dispensable amino acids. In fact, individual groups of rats which were fed diets that were devoid of one of the following: glutamic acid, proline, aspartic acid, and asparagine, alanine, serine, or glutamine and glutamic acid, grew maximally. Thus, no minimal requirements could be established for the above amino acids. However, a minimal requirement for arginine was found to be about 0.3% of the diet even when proline and glutamic acid were both added in excess.