Occurrence of alpha- and beta-nortestosterone residues in the urine of injured male cattle.

The administration of anabolic steroids, for the purposes of growth promotion, to food-producing animals is banned in the EU. Among the compounds covered by this prohibition is ss-nortestosterone (beta-NT). This hormone is known to occur naturally in stallions and boars, and its main bovine metabolite, alpha-nortestosterone (alpha-NT), occurs naturally in pregnant cows and neonatal calves.