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  • 1
    ISSN: 1431-4630
    Schlagwort(e): Key words Steroid hormones ; Anabolic implant ; Steers ; Beef
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Abstract  Profiles of steroid hormones (androgens, estrogens, progestogens and corticoids), their precursors and metabolites were analyzed in nine beef samples obtained from steers which had received the anabolic implant Synovex-S (200 mg progesterone plus 20 mg estradiol benzoate) and in nine samples from control steers. Analysis of phenolic steroids was performed by enzyme immunoassay after separation by HPLC. Neutral steroids were determined by GC-MS. Concentrations of the hormones progesterone and 17β-estradiol, of their precursors and metabolites (pregnenolone, 17α-hydroxyprogesterone, dehydroepiandrosterone, androstenedione, epitestosterone, α-androsterone, 17α-estradiol, and estrone) and of the corticosteroids cortisone and hydrocortisone did not differ significantly between treatments (P〉0.05) but the ratio of 17β-estradiol to its metabolites and the cortisone/hydrocortisone ratio were significantly higher in beef from treated steers (P〈0.01). Concentrations of testosterone and 5α-dihydrotestosterone were below the determination limits (10 ng/kg and 20 ng/kg, respectively) in both treated and control steers.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Zeitschrift für Lebensmittel-Untersuchung und -Forschung 207 (1998), S. 183-188 
    ISSN: 1431-4630
    Schlagwort(e): Key words Hormone pattern ; Slaughter age ; Bulls ; Steers ; Beef
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Abstract  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.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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