Differences in natural steroid hormone patterns of beef from bulls and steers

This investigation gives an overview of the concentrations of naturally occurring androgens, progestogens, corticesteroids, and their precursors and metabolites in meat from bulls and steers. A recently developed gas chromatography-mass spectrometry (GC-MS) method with improved sensitivity for steroid analysis was used. Eighty-two beef samples were analyzed using the GC-MS method. Beef from bulls contained higher concentrations of testosterone, which is an anabolic androgen, and its metabolite epitestosterone (P < .01) and the androgen precursor dehydroepiandrosterone (P < .05) than beef from steers. Beef from steers contained higher (P < .05) concentrations of the basic hormone precursor pregnenolone and cortisol, which is a catabolic corticosteroid, than beef from bulls. A classification of an unknown beef sample to one of the categories (bull or steer) was possible in most cases (>90%) using a masculinity index (MI) that was calculated using the concentrations of testosterone, epitestosterone, and pregnenolone. Because the hormonal status of beef cattle is related to meat quality characteristics, such as tenderness or fat and protein distribution, the MI may contribute to meat quality assessment and meat quality control. Key Words: Beef, Steers, Bulls, Androgens, Progestogens, Corticoids