Sperm abnormalities in post-thawed semen of Tunisian Arab stallions.

This research investigated the morphological changes in sperm of Tunisian Arab stallions after freezing and thawing. The study found that the freezing-thawing process contributes to an increase in abnormal sperm, which impacts the quality of the semen.

Introduction

• The study seeks to understand the impact of freezing and thawing on the morphology of stallion sperm. This investigation becomes important considering that artificial insemination in equine breeding often involves freezing and thawing of semen.

Methodology

• Forty-two ejaculates were collected from nine different Tunisian Arab stallions aged between 9 to 24 years, over a period of two years (2009-10).
• The semen samples were frozen and subsequently thawed. The morphological features of the sperm were studied after staining with eosin-nigrosin, a common stain used for assessing sperm viability.
• The percentages of abnormalities in various parts of the sperm including the head, mid-piece, flagella (tail) and also sperm with droplets were determined.
• The investigation used a variance analysis carried out with SAS software to handle statistics and derive conclusions.

Results

• The study found that all features of sperm morphology varied among ejaculates within each individual stallion as well as between different stallions. This indicates that both intrinsic and extrinsic factors play a role.
• The percentage of flagella abnormalities and total abnormal sperm differed significantly between young and old stallions.

Conclusion

• The study concludes that the process of freezing and thawing increases the number of abnormal sperm in the semen. This cellular alteration is seen in stallions both old and young.
• The change in sperm morphology consequently affects the overall quality of the thawed semen, reducing its viability for successful insemination and leading to potential reproductive issues.