EN
The aim of the study was to determine the effects of platelet-activating factor (PAF) on selected quality parameters of cryopreserved bull semen with reduced sperm motility used for artificial insemination. The aim of experiment 1 was to identify the optimal concentration of the phospholipid able to preserve sperm viability. Cryopreserved semen was treated with different PAF concentrations: 1x10-5M, 1x10-6M, 1x10-7M, 1x10-8M and 1x10-9M. The experiment demonstrated that PAF at concentration 1x10-9M increased most the sperm viability parameters (motility parameters, plasma membrane integrity and mitochondrial function) after 120 min of incubation of thawed semen at 37oC. Cryopreserved bull semen with reduced sperm motility (below 70%) was supplemented with PAF in a concentration of 1x10-9M. A statistically significant increase in sperm motility, percentage of linear motile spermatozoa and VSL value was observed after 120 min incubation of sperm with 1x10-9M PAF. Sperm supplementation with PAF also had positive effects on plasma membrane integrity and percentage of spermatozoa with preserved mitochondrial transmembrane potential, but the differences were not statistically significant. The results indicated positive effects of PAF supplementation at a concentration of 1x10-9M on the selected sperm quality parameters in cryopreserved bull semen with reduced motility.