Liquid storage and freezing of semen from New Forest and Welsh Pony stallions.

This research investigates the effectiveness of sperm storage and freezing techniques, specifically targeting semen from New Forest and Welsh Pony stallions. The findings show that different methods have varied effects on sperm motility, sperm velocity, and morphological features.

Objective and Methodology

• The primary aim of this research was to investigate two methods of stallion semen storage and freezing, with an emphasis on their impact on motility and morphology of the sperm.
• The study was divided into two experiments. The first involved ejaculates being diluted with an extender (either D11 or SME) before storage at +5 degrees C. The second involved packaging the sperm in lactose-egg-yolk-glycerol extenders before freezing, followed by thawing.
• The researchers analyzed various parameters of the sperm at different stages, including progressive motility, average path velocity, and morphological attributes.

Findings and Implications

• The results from the first experiment indicated that the method of storage influences the sperm’s motion characteristics. Specifically, semen stored in SME showed significantly superior progressive motility and average path velocity compared to D11 after 6, 18, and 42 hours.
• However, the D11 extender seemed to preserve sperm morphology and acrosome integrity better than SME over a storage time. This aspect is significant, as sperm morphology and acrosome integrity are crucial for successful fertilization.
• The second experiment demonstrated that the freezing and thawing process significantly reduced the sperm’s motility, velocity, and percentage of morphologically normal spermatozoa. However, the acrosome morphology appeared to be unaffected.
• This finding suggests that semen freezing protocols may need to be updated to better preserve motility and morphology. The freeze/thaw process is widely used in assisted reproduction techniques, including artificial insemination and in-vitro fertilization, where sperm quality is critical.