Development of the genital microflora in stallions used for artificial insemination throughout the breeding season.

This research investigates the changes in the microbial population of the genital mucosa and semen in male horses used for artificial insemination during one breeding season. The study observes marked changes over time, with an increased microbial growth throughout the breeding season. However, the microbes found were generally non-pathogenic, with pathogenic agents only occasionally present.

Research Goals

• The main goal of this research was to study and understand the alterations in the microbiological population within the genital mucosa and semen of stallions used for artificial insemination over one breeding season (February to August).

Methodology

• Sixteen stallions were observed for this study.
• The bacteria found in the urethral opening, urethral fossa, penile sheath, and semen of these stallions were swab-collected at four-week intervals. The identification of microbial agents was done using MALDI-TOF-MS.
• The study also examined the motility of the semen and the percentage of morphologically normal spermatozoa.

Findings

• The semen of the stallions showed noticeable changes over time.
• In 14.3% of genital swabs and 25% of ejaculates, there was no microbial growth noted.
• The total microbial growth intensity showed an increase as the season progressed.
• The research identified between 1.4 on average microbial species in February and 3.3 in August from the penile sheath. From semen, an average of around 1.1 microbial species in February and 2.9 in August were obtained.
• It was observed that the number of microbial species was greater in the penis sheath and urethral fossa than in the urethral opening and semen.

Bacterial Flora

• The microbial flora consisted mainly of non-pathogenic aerobic and anaerobic bacteria, like coagulase-negative staphylococci, alpha-haemolytic streptococci, and coryneforms.
• Potentially pathogenic agents like E. coli and Ps. aeruginosa were occasionally found, suggesting infection was not a common occurrence.
• The microbial flora was found to have no significant relation with seminal characteristics.

This research lends insight into the microbial dynamics within the genital microenvironment of reproductive male horses and may provide useful information for the management of stallion fertility and insemination procedures.