This Government Ordinance, which is composed of 13 articles and one Annex, concerns the prohibition of the use in stockfarming of certain substances with hormonal or thyrostatic action and beta-antagonists. It is prohibited (i) to give to livestock animals or aquaculture animals substances with thyrostatic, estrogen, androgen or gestagen action and beta-antagonists; (ii) to place on the market livestock or aquaculture animals if the substances specified above-mentioned have been found or given to these animals; (iii) to process meat from such animals.