Investigation of the Effects of Storage Period for Frozen Bull Semen on In Vitro Embryo Production

Abstract

The aim of this study was to investigate some spermatological parameters of frozen Brown Swiss bull semen 32 years ago by flow cytometry and to determine how storage time in liquid nitrogen affects in vitro embryo production ratios. For this purpose, early necrotic, necrotic, viable and apoptotic spermatozoa concentrations were analyzed using the Flow Cytometry and then the in vitro fertilization abilities of these sperms were investigated. AnnexinV/PI-FITC (R) was used to determine the apoptotic changes with flow cytometric analysis. Oocytes were obtained from slaughtered cows in a local abattoir. Brown Swiss semen, frozen in the last two years, were used for the control group. Early necrotic spermatozoa levels in semen frozen 32 years ago were lower but necrotic spermatozoa levels were higher than in the control group, but the opposite result was encountered in the control group (P<0.01) according to flow cytometry findings. The cleavage ratio in vintage spermatozoa was found to be lower than in the control group (P<0.0z), the blastocyst ratio was also lower than in the control group (P<0.01). As a result, it was observed that some spermatological parameters can be changed negatively and it can be said that a long storage period may lower the fertility capabilities of Brown Swiss bull semen.