Bacteria may deteriorate progressive motility of bovine spermatozoa and biochemical parameters of seminal plasma

and bacteria are partially known. The aim of our study was to evaluate qualitative bacterial composition of fresh bovine semen and to
reveal associations amongst the quantity of bacteria (Colony Forming Unit – CFU/mL) present in bovine ejaculates with progressive
motility of spermatozoa and biochemical parameters of seminal plasma. Fresh semen (n=20) was collected from Holstein-Friesian bulls.
Progressive motility (PROG≥25µm/s) was analysed using Computer-assisted sperm analysis (CASA). Seminal plasma was separated
and subjected to assessment (Randox RX Monza analyzer) of following biochemical parameters: Magnesium (Mg), Calcium (Ca),
Phosphor (P), Urea, Aspartate transaminase (AST), Alanine transaminase (ALT), Alkaline phosphatase (ALP), Cholesterol, Bilirubin,
Triglycerides, Albumin and Uric acid. The identification of bacteria showed the prevalence of the genus Staphylococcus. The Pearson
correlation analysis showed a negative significant (P<0.001) correlation between CFU and PROG. Further, positive significant
correlations were observed amongst PROG and biochemical parameters (P<0.01 in case of Mg, Urea, ALP, ALB; P<0.05 in case of Ca,
ALT, Bilirubin and Uric acid). The results show negative significant correlations amongst CFU and biochemical parameters (P<0.001 in
case of Mg; P<0.01 in case of ALT, ALP and P<0.05 in case of Uric acid). In conclusion, our results reveal that bacteria may affect not
only on the sperm motility, but also on the composition of the seminal plasma. More detailed studies are needed to reveal the
mechanisms of interaction amongst semen and bacteria.