Urinary Concentrations of Steroids in Bulls under Anabolic Treatment by Revalor-XS® Implant.

Despite the European ban of using anabolics in food-producing animals, growth promoters might still be illegally used in the European Union. To control the food chain and guarantee consumers' health, there is a need of highly sensitive analytical methods for the identification of marker residues of such treatments. In the present study, a group of bulls ( = 16) received trenbolone acetate (200 mg) and estradiol (40 mg) by a commercial ear implant during a time range of 71 days, and a second group ( = 16) was kept for control. The aim of the research was to measure the residual urinary concentrations of the administered drugs (-trenbolone and -estradiol), their main metabolites (-trenbolone and -estradiol), and possible alterations of the urinary profile of other endogenous hormones metabolically related. The analytical method was based on liquid chromatography-tandem mass spectrometry. Results showed average urinary concentrations of -trenbolone and -estradiol during treatment in the range of (0.81 ÷ 2.1) ng mL and (0.96 ÷ 4.4) ng mL, respectively, whereas -trenbolone and -estradiol exhibit urinary concentrations lower than 0.22 ng mL in both cases. Data obtained from the urinary profiles of endogenous steroids indicate that they could be useful to indirectly detect the ongoing treatment.