Effect of Epidermal Growth Factor (EGF) on Cryopreserved Piedmontese Bull Semen Characteristics

SIMPLE SUMMARY: This study aimed to investigate bull thawed semen characteristics under the effect of different concentrations (0, 50, 100, 200, and 400 ng/mL) of EGF being added to the extender prior to freezing. Semen samples collected from four bulls for 8 weeks were pooled, diluted with Bullxcell(®) extender supplemented with EGF at different concentrations, cooled, and frozen. After thawing, semen was examined for different parameters, including motility, kinetics, vitality, integrity, mitochondrial and antioxidant (SOD) activities, mucus penetration distance, as well as in vitro fertilizing capability. EGF incorporation in semen extender improved the total, progressive, and rapid motility and the sperm velocity at 50, 200, and 400 ng/mL after different incubation periods (from 1 to 4 h). We conclude that EGF supplementation to bull sperm extender before cryopreservation has an improving effect on sperm motility and kinetics without affecting sperm parameters. ABSTRACT: The purpose of this study was to determine the effect on fresh and post-thaw beef bull semen quality of the supplementation of epidermal growth factor (EGF) to the semen extender at various concentrations (0-control, 50, 100, 200, and 400 ng/mL). For 8 weeks, sperm was collected from four fertile bulls, yielding a total of 32 ejaculates. Semen samples were pooled, diluted with Bullxcell(®) extender, and then cooled, equilibrated, and frozen. After thawing, semen was tested for motility and velocity parameters. Furthermore, semen was evaluated for vitality, integrity, mitochondrial and antioxidant (SOD) activities, mucus penetration distance, and in vitro fertilizing capability. The supplementation with EGF prior to cryopreservation improved the total sperm motility at various concentrations over long incubation periods (from 1 to 4 h). Interestingly, EGF addition improved both progressive and rapid motility, particularly at 50, 200, and 400 ng/mL. In addition, EGF, primarily at 200 and 400 ng/mL, significantly increased several velocity parameters after different incubation periods. We can conclude that adding EGF to bull sperm extender before cryopreservation has a positive stimulatory effect on sperm motility without affecting vitality, integrity, or in vitro fertilizing capability.