Excretion profile of boldenone and its metabolites after oral administration to veal calves Original Research Article

The residue profiles of boldenone (17β-Bol), its epimer (17α-Bol) and the related compound androsta-1,4-diene-3,17-dione (ADD), were investigated by liquid chromatography–tandem mass spectrometry (LC–MS/MS) in urine of male calves orally treated with boldenone, boldenone esters, and/or ADD. In all the experiments with the administered steroids residues of 17α-Bol decreased rapidly after end of treatment; detectable amounts of 17α-Bol were however noticed along the withdrawal observation period after end of treatment. Differently, residues of 17β-Bol were detectable only shortly after administration. This in vivo research concerning oral treatments of cattle with boldenone related substances proves ADD to be a very active boldenone precursor in bovine animals.