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