Assessment of extent of apoptosis and DNA defragmentation in chilled semen of stallions during the breeding season.

The research article presents a study focusing on the impacts of chilling on stallion semen, specifically examining apoptosis (cell death) and DNA defragmentation. The findings indicated that semen characteristics were retained until 24 hours of chilling for Arabian stallions and until 48 hours for coldblood stallions.

Objective and Methodology of the Study

• The study aimed to investigate the level of apoptosis and DNA defragmentation in equine semen that was diluted and chilled to +4°C.
• Semen was collected from nine fertile stallions, which included four Arabian thoroughbreds and five coldbloods.
• The semen samples were examined immediately after collection and at intervals of 24, 48, 72, 96, and 120 hours.
• Researchers evaluated semen for volume, sperm concentration, percentage of viable sperm, progressive motility, and morphology.
• They used flow cytometry, a technique that allows for the detailed examination of cells, to determine DNA defragmentation and cell membrane integrity of spermatozoa.

Key Findings of the Research

• The initial tests did not show significant differences amongst the stallions, except for progressive sperm motility. This was notably higher in Arabian stallions.
• In the semen of Arabian stallions, there was a significant decrease in the percentage of live spermatozoa at 72, 96, and 120 hours of chilling. There was also a significant increase in the number of spermatozoa with DNA fragmentation after 24 hours of storage.
• In contrast, in the coldblood stallions’ semen, the percentage of live spermatozoa decreased significantly at 96 and 120 hours. The DNA fragmentation increased significantly at 48 hours.
• From these results, it can be inferred that Arabian stallions’ semen retained original characteristics for up to 24 hours when chilled to +4°C, whereas coldblood stallions’ sperm retained the qualities for up to 48 hours.

Implications of the Study

• The findings of the study are essential for horse breeding practices. They suggest that the chilling time of semen should be considered for successful fertilization, depending on the breed of the stallion.
• The research contributes to understanding cell death (apoptosis) and DNA fragmentation in semen, which are important factors in sperm viability and breeding success.
• The findings could help develop optimal semen storage techniques to improve breeding outcomes.