Natural hormone patterns of meat from steers and bulls depending on slaughter age

 Natural patterns of steroid hormones (androgens, progestogens and corticoids), their precursors and metabolites were analysed in 48 beef samples with gas chromatography-mass spectrometry (GC-MS). Muscle tissue samples were taken from steers (n=23) and bulls (n=25) of the breed German Simmental, which were slaughtered at different ages (151–705 days of age). Concentrations of testosterone, dehydroepiandrosterone (DHEA), progesterone, cortisol and cortisone in beef from steers were not dependent on age, whereas pregnenolone, androstenedione and epitestosterone increased significantly with increasing slaughter age (r=0.48, P<0.05;r=0.60, P<0.01 and r=0.62, P<0.001, respectively). The concentrations of the metabolite androsterone tended to increase as well. The differences were not significant, however, due to the high level of variability. In beef from bulls cortisone concentrations were inversely correlated with increasing slaughter age (r=–0.47, P<0.05). The decrease from day 175 to day 260 was significant. Testosterone was positively correlated with increasing age (r=0.46, P<0.05). The tissue concentrations at the different slaughter ages did not differ significantly, however. The Δ5-precursors pregnenolone and DHEA tended to show a minimum at the age of 370 days, followed by a significant increase. No age dependence of the progesterone, androstenedione, androsterone, epitestosterone and cortisol concentrations could be detected. Analysis of steroid hormone concentrations may form part of a reliable method for estimating the age of slaughtered cattle. In this study, the age of samples was estimated to within ± an average of 10 weeks. Received: 29 December 1997 / Revised version: 1 March 1998