Effects of boron added bull semen extender on post-thaw spermatological parameters

In this research, post-thaw effects of bull semen extenders including different amounts of boron (sodium pentaborate) on total motility (TMOT), progressive motility (PMOT), kinetic parameters of spermatozoa (VCL, VSL, VAP, LIN, STR, WOB, ALH, BCF), plasma membrane and acrosome integrity (PMAI) and DNA fragmentation index (DFI) were evaluated. Eight ejaculates were examined from four different bulls. Each ejaculate was split in to five aliquots and extended with standard Tris extender (Control) and 0.4 g boron with 0.5 g glucose (Group 1) 0.5; 0.7; 0.9 g boron without glucose (Group 2, Group 3 and Group 4 respectively) were used as experimental groups. After thawing TMOT, PMOT, kinetic traits of spermatozoa, PMAI and DFI were determined. According to motility and progressive motility (66.04%, 50.79%), Group 1 had higher values than the others, but differences between groups were not statistically significant (P>0.05). The highest values of VSL, LIN, STR and WOB were determined (28.15 μm/s, 42.98%, 71.69%, 59.71%) in Group 1 (P<0.05). While other kinetic traits of spermatozoa were higher numerically in Group 1 than the other groups, differences between groups were not statistically significant (P>0.05). The highest PMAI value was determined as 60.84% in Group 1 (P>0.05). The DFI rates were found similar in all control and experimental groups (P>0.05). In conclusion, it was observed that the boron (sodium pentaborate) has positive effects on post-thaw movement and structural traits. In addition, boron has no detrimental effect on DNA fragmentation index in semen freezing. Thus, boron could be used as an alternative semen extender compound.