Evaluation of cellulose acetate/nitrate filters for the study of stallion sperm motility.

The research investigates the effectiveness of specific filter pore sizes in testing stallion sperm motility and how bacterial supernatants might influence it, thereby suggesting its potential use in evaluating stallion fertility.

Research Methodology and Experiment

• The semen from stallions was diluted in a Hepes-supplemented buffer and placed in a Sykes-Moore chemotaxis chamber, a tool used for evaluating cell movement.
• The chambers were then incubated in a humidified atmosphere at a particular temperature of 37 degrees Celsius for either 1 or 2 hours, allowing the spermatozoa to swim through filters.
• Three types of filters were used in this experiment. The filters had different mean pore sizes, including 3, 5, and 8 microns.

Findings and Observations

• Spermatozoa managed to infiltrate filters of all three sizes.
• It was observed that the distance traveled by the spermatozoa was greater with each increase in pore size.
• However, the time of incubation, whether it be one or two hours, did not impact the distance travelled significantly.
• Examinations were conducted on extended semen from stallions of varying fertility to identify the minimum concentration of spermatozoa required to penetrate 3-micron pore filters.
• The progression of sperm into the filter reflected the overall motility, or movement capability, of the ejaculate.

Potential Consequences and Additional Findings

• The research suggests that, given the accepted correlation between motility and fertility, this method can be a viable way of estimating the fertility of a stallion – particularly by observing the ability of sperm to move through 3-micron pore filters.
• Bacterial supernatants from Streptococcus zooepidemicus and Enterobacter aerogenes cultures were found to hinder sperm progression into 3-micron filters, decreasing motility after 2 hours of incubation in particular dilutions.
• Interestingly, the bacterial supernatants from the two types of bacteria were observed to be chemokinetic – or movement stimulating – to horse neutrophils, a type of white blood cell, without affecting their viability.