Response to cooling of pony stallion semen selected by glass wool filtration.

The research investigated the effectiveness of using glass wool filtration to separate sperm in pony stallion semen samples and compared this method to just cooling the diluted samples. The study concluded the glass wool filtration method selected spermatozoa with higher motility and mitochondrial viability, and retained membrane integrity, improving results up to 24 hours.

Introduction and Methodology

• The objective of this research was to examine two methods of handling pony stallion semen: conventional cooling and glass wool filtration.
• The study involved the use of 18 semen samples provided by six pony stallions of the Brazilian breed.
• The parameters under examination included pH, osmolarity, total motility, membrane functionality (known as HOST), membrane integrity (or CFDA/PI), morphology, and mitochondrial viability. These parameters were assessed in fresh samples, and in samples cooled at 5°C for 24 and 48 hours.
• The cooled samples were divided into two: a control group, which was just cooled, and a filtered group, in which the semen was filtered through glass wool before cooling.
• The semen that was held back, or “retained”, by the glass wool barrier was also examined within the context of the study.

Results

• After 24 hours of cooling, total motility in the control group was 35.5%, whereas it was 43.3% in the filtered group and 10% in the retained group. Thus, the filtered group exhibited significantly higher motility (p < .0001).
• Further, at the CFDA/PI test, sperm membrane integrity was 37.9% in the control group, 44.8% in filtered, and 14.8% in the retained group, showing again that the filtered group retained significantly higher integrity (p < .0001).

Conclusions

• These results established that glass wool filtration effectively separates and selects for higher quality spermatozoa in terms of motility, mitochondrial viability, and membrane integrity.
• This superior performance was seen up to 24 hours of cooling. However, the benefits of filtration over cooling alone were not clearly evident after 48 hours of cooling.