Effect of 19-norandrostenololylaurate on semen characteristics of colts.

This research studied the impact of the anabolic steroid 19-norandrostenololylaurate on the semen characteristics of Finnhorse colts over a long period of time. The study established that, whilst steroids can adversely affect semen characteristics, these changes are reversible upon cessation of steroid treatment.

Introduction and Methodology

• The study examined the long-term effects of 19-norandrostenololylaurate, an anabolic steroid, on semen characteristics of Finnhorse colts (young male horses).
• The research was conducted in three separate experiments where semen was initially collected from the colts when they were 24 months old and then twice a year afterwards.
• In the first experiment, doses of either 500 mg or 100 mg of the steroid per animal were administered every third week from the time the colts were 12 or 16 months old to 24 months of age.
• In the second experiment, colts were treated either with a dose of 1 mg/kg every 3rd week or 0.3 mg/kg every week from age 7 months to 12 months.
• In the third experiment, the animals were treated from 3 months to 8 months of age, and the first semen collection was done 16 months after the last treatment.

Findings

• In the first experiment, 3 out of 5 colts in the group treated with 500 mg of anabolic steroids every third week showed zero sperm count in their first semen collections after the end of treatment.
• The other two colts in the same group had low sperm numbers and a high count of proximal droplets as compared to the control animals.
• The adverse impact was less in the group given 100 mg of the steroid, signifying that the severity of impact is dose-dependent.
• However, the adverse changes in the semen characteristics were found to be reversible. Four months after the end of treatment, all of the colts had spermatozoa present in their ejaculates.
• Two years after treatment had ceased, the sperm counts in treated animals were even higher than in the control group.
• In the second experiment, animals treated with a lower dosage of 0.3 mg/kg every week were less affected than those treated with 1 mg/kg every three weeks.
• In the third experiment, there were no significant differences observed in the semen parameters of any of the groups.

Conclusion

• The research concluded that while steroid treatment can have negative effects on semen characteristics, these effects are reversible following the end of treatment, at least in the groups treated at age 7-25 months.
• In fact, in some cases, cessation of treatment may even lead to sperm numbers exceeding those in the control group after a sufficient time period has passed.