Like in the poultry industry, there is an active lobby to allow use of synthetic amino acids, although this is strongly opposed by most of the organic movement. (austorganic.com)
This change has been in effect for just over two years, but it is important to note that methionine is the only synthetic amino acid permitted in livestock feed as it is essential for the growth and well being of the animal. (austorganic.com)
«New synthetic amino acid for emerging class of drugs.» (sciencedaily.com)