Effects of different concentrations of Pseudomonas aeruginosa on boar sperm quality

Bacteriospermia in boar ejaculates is a frequent finding that compromises the sperm quality and, consequently, causes economic losses in swine industry. The present study sought to evaluate the effect of different concentrations of Pseudomonas aeruginosa on boar sperm quality over a storing period of 11 days at 15–17 °C. Ten commercial seminal doses coming from post-pubertal and healthy boars were artificially inoculated with different infective concentrations of P. aeruginosa, ranging from 2 × 108 to 2 × 104 cfu/mL. Negative controls were non-inoculated doses. Sperm quality, assessed as sperm motility (CASA), sperm viability, acrosome integrity and pH, as well as the bacterial growth, were checked after 0, 1, 2, 4, 7, 9 and 11 days of storage at 15–17 °C. Results obtained showed significant decreases in the percentages of total and progressive sperm motility, sperm viability and acrosome integrity in the greatest infective concentrations (2 × 107 and 2 × 108 cfu/mL), when compared to the negative control. In contrast, there was no effect on seminal pH throughout the experiment. Results indicate the presence of P. aeruginosa in boar semen, apart from being a potential source for the spread of infectious diseases and harmful impact on sows, negatively affects the longevity and fertilizing ability of boar sperm when present in high concentrations. Thus, P. aeruginosa causes deleterious effects on boar sperm quality during liquid storage at 15–17 °C, thus strict hygienic measures must be implemented in boar studs to minimize bacterial concentration of semen doses.