The board of the U.S. National Organic Program is considering a proposal to ban synthetic methionine from organic diets, following an earlier decision regarding synthetic lysine. The decision has been deferred following presentations made by the program’s Methionine Task Force, which includes nutritionists and producers of organic products.

Deletion of synthetic methionine from an organic diet to produce specialty organic eggs would result in an additional cost of $100 per ton, compared with comparable formulations using organic ingredients but allowing inclusion of 0.35% synthetic methionine.


Reducing specifications for dietary sulphur-containing amino acids could reduce the incremental cost to $50 per ton, although this would result in a corresponding reduction in egg size and egg numbers. Assuming a differential of $75, representing deletion of synthetic methionine and moderate relaxation of nutritional specifications, the cost to a producer would be $900 per day for 100,000 hens, or between 13 to 15 cents per dozen, depending on the level of flock production.

Supporters of continuing to allow synthetic methionine in organic production point out that the ingredient is derived by microbial fermentation and that it is absorbed and metabolized in the same way as plant-sourced methionine.