Sex steroid levels in urine of cattle of different ages: evaluation of abuse control procedures

Abstract

Levels of several natural urinary steroids have been determined in the urine of a large number of animals of different cattle categories in the context of steroid abuse in beef production. Bovine animals of different breeds, sex and age included in the Slovene national residue detection plan for steroid abuse were studied. Urine from 120 males and 174 females was analysed. Urinary boldenone, boldione, androstenedione, equiline, medroxyprogesterone, medroxyprogesterone acetate, melengestrol acetate, progesterone, stanozolol, trenbolone, trenbolone acetate, 17α-ethinylestradiol, 17α-methyltestosterone, epitestosterone, 17β-estradiol, testosterone, and nandrolone were determined by LC-MS/MS. Epitestosterone was found in all bulls; while the proportion of animals containing testosterone and androstenedione increased with age. Testosterone was not detected in bulls less than 5 months of age. Epitestosterone levels, however, were not age dependent. The ratio of testosterone to epitestosterone thus increased with age, from 0.13 ± 0.09 at 1–7 months to 0.42 ± 0.10 at 25–38 months. It was significantly (p < 0.01) higher in bulls above 13 months than in younger animals. In contrast to males, no urinary testosterone was found in females, whereas epitestosterone, androstenedione, progesterone and estradiol were present. The proportion of animals of various age groups in which epitestosterone was detected ranged from 68% to 100%, but the differences were not significant. The presence of both estradiol and progesterone in the same sample was not observed in any animal. The results of this study could be helpful in determining physiological urinary steroid levels in order to provide a baseline for the control of steroid abuse in beef production.

Keywords:

• steroids
• cattle
• urine
• steroid abuse
• beef production
• LC-MS/MS

Acknowledgements

The authors are thankful to Dr Roger H. Pain for English editing and suggestions.

Funding

The authors acknowledge The Slovenian Research Agency [grant number P4-0053] and The Administration of the Republic of Slovenia for Food Safety, Veterinary and Plant protection which enabled the study.