Semen characteristics after vasectomy in the ram

Area of Science:

• Veterinary Science
• Reproductive Biology
• Animal Husbandry

Background:

• Vasectomy is a common sterilization procedure in male animals.
• Understanding the timeline of infertility post-vasectomy is crucial for effective population control and breeding management in livestock.
• Previous studies have not fully elucidated the long-term semen characteristics following vasectomy in rams.

Purpose of the Study:

• To monitor changes in semen characteristics of vasectomized rams.
• To determine the presence of infertility 14 days after vasectomy.
• To assess the long-term efficacy of vasectomy in achieving azoospermia in rams.

Main Methods:

• Five cross-breed rams (18-30 months old) were used.
• Semen was collected weekly via artificial vagina for 7 months (2 months pre- and 5 months post-vasectomy).
• Parameters analyzed included volume, concentration, total sperm count, motility, morphology, and viability (SYBR-14/PI staining).

Main Results:

• A significant decrease (P < 0.05) in ejaculate volume, total sperm count, and normal sperm morphology was observed 14 days post-vasectomy.
• Sperm motility and viability were undetectable after vasectomy, with a continuous decline in normal spermatozoa and an increase in loose heads.
• Despite weekly collections for 5 months, azoospermia was not achieved in any ram; post-mortem examination revealed spermatocele and sperm granulomas.

Conclusions:

• Vasectomy in rams causes a rapid and significant decline in semen quality, with no motile or viable spermatozoa detected 14 days post-surgery.
• Complete infertility (azoospermia) is not consistently achieved even 5 months after vasectomy in rams.
• The presence of spermatocele and sperm granulomas suggests incomplete blockage or recanalization, necessitating further evaluation for long-term efficacy.