Studies on the Persistence of Estradiol Benzoate and Nortestosterone Decanoate in Hair of Cattle Following Treatment with Growth Promoters, Determined by Ultra-High-Performance Liquid Chromatography–Tandem Mass Spectrometry

The study investigated the persistence of estradiol benzoate and nortestosterone decanoate in cattle hair following treatment with growth promoters, using liquid chromatography-tandem mass spectrometry (LC–MS/MS). The research found that while this method could detect steroid esters in some hair samples, it did not consistently identify all treated animals. Detection was influenced by factors such as the location of hair sampling relative to the injection site, the timing of sampling post-treatment, and the dosage administered. The study highlighted the complexity of steroid ester accumulation in hair, suggesting that it occurs through multiple pathways, including blood, sweat, and sebum. The findings provided insights into the mechanisms of steroid persistence in hair, which could aid in distinguishing between illicit treatment and natural hormone production in cattle.