The effect of exogenous anabolic steroids on growth performance, testicular and seminal characteristics of yearling Boer goat bucks

The effect of anabolic steroid treatment on young Boer goat bucks (12 months of age; mean body weight of 47.0 ± 3.8 kg) was investigated. Bucks were individually housed and randomly allocated to two treatment groups and fed a pelleted maintenance diet (8.5 MJ ME/kg and 13% CP). Bucks in the first group (n = 9) received a weekly i.m. injection of 25 mg Deca-durabolin (testosterone) for a total period of 16 weeks. The remaining bucks (n = 10) served as the controls. At the end of the 16-week treatment phase an additional 12 week recovery monitoring phase (no treatment) was implemented. During the trial semen was collected (artificial vagina) weekly, where semen volume, colour, pH and sperm density and motility was recorded. The body parameters recorded weekly included body weight, scrotal circumference and volume. The body parameters found to be significantly (P < 0.05) affected by treatment with the anabolic steroid, was scrotal circumference and volume. This degeneration of the scrotal measurements was ascribed to the negative feedback system induced by the exogenous anabolic steroid treatment (androgenic effect). By the end of the recovery period, the difference in scrotal circumference and volume between the treatment groups had decreased to 7% - with the treated bucks still recording a significantly (P < 0.05) lower scrotal volume, compared to the control group (584.4 ± 87.3 ml vs 640.0 ± 81.0 ml respectively). Despite this reduction in scrotal circumference and volume none of the seminal parameters recorded in the trial (i.e. sperm motility, semen volume and pH, sperm concentration and percentage live sperm) were significantly affected by the steroid treatment. It would also seem as if the inhibitory effect of steroid treatment on testicular development was only temporary and that young males can recover, without any apparent loss in fertility, as measured by semen quality. The lack in body weight response could possibly be ascribed to the age of the animals and the relatively low energy content of the diet.