Effect of breeding activity on the microflora of the external genitalia and in the semen of stallions, and the relationship between micro-organisms on the skin and on the external genitalia.

The research article evaluates how breeding activities could influence the composition of the microbial population in a stallion’s external genitalia and semen. The study also investigates the correlation between microbes found on the stallion’s abdominal skin and those on the external genitalia.

Overview of the Experiments and Findings

• The research consists of three experiments performed to understand the effects of breeding activities on microbial population in stallions’ external genitalia in different settings.
• The first experiment involved gathering microbiological samples from the external genitalia of 41 stallions used for both natural cover and semen collection (BST), and 18 non-breeding stallions (NBST). The study found a higher frequency of potentially harmful species in the BST group. The age of the stallions did not impact the number of different varieties of micro-organisms found in both BST and NBST groups.
• The second experiment compared the microbial content of semen and external genitalia from 23 BST stallions. Majority of the microbes found on the external genitalia were also found in the semen, though at a lower prevalence. Some microbes were found in the semen but were absent in the external genitalia cultures, indicating possible contamination during sample collection.
• The last experiment dealt with 31 stallions and found a larger variety of microbes on the external genitalia than on the ventral abdominal skin that comes in contact with the penis or the thorax skin. Potentially harmful bacteria, with the exception of E.coli, were only isolated from the external genitalia and not the skin.

Conclusions from the Research

• This research suggests that breeding activity increases the number of species found on the external genitalia of stallions.
• Most of the species found on the external genitalia were also present in semen, although in a less prevalent manner.
• Interestingly, there seems to be additional contamination of semen during its handling, as some species found in semen were not present on the external genitalia.
• Though many types of microbes were found on both the penis and the ventral abdominal skin, the skin doesn’t appear to provide a conducive environment for the growth of potentially pathogenic bacteria.
• Only E.coli was identified as a potentially pathogenic bacterium that managed to thrive on both, the external genitalia and the skin of the stallions.