Effects of Type of Extender and Freezing Method on Bovine Semen Post-Thawed Quality Characteristics and Bacterial...

Despite the considerable improvement in sperm cryopreservation regarding the procedures and cryoprotectants, the post-thawed semen quality characteristics still are far lower than the fresh semen sample. The current study aimed to investigate the efficacy of two semen extenders including ANDROMED (soy lecithin-based) and TRILADYL CSS (egg yolk-based) in combination with manual and automatic freezing programs on preserving post-thawed Bovine semen quality characteristics and bacterial contamination. The semen samples were cryopreserved via manual and automatic freezing using different extenders after passing the initial quality examination. Sperm quality characteristics and bacterial contamination were evaluated in fresh and post-thawed semen samples. The results demonstrated that regardless of the freezing program, the egg yolk-based extender is superior in preserving semen quality characteristics during cryopreservation; however, the post-thawed semen bacterial contamination was higher in semen samples extended in egg yolk-based extender (p < 0.0001). Moreover, the semen post-thawing quality characteristics were significantly higher in automatic compared to manual freezing (p < 0.0001). Regarding the interaction effects, the semen samples diluted with egg yolk-based extender and frozen via automatic freezing showed the highest post-thawing quality characteristics highlighting the higher suitability of egg yolk versus soy lecithin-based semen extender and also automatic versus manual freezing in preserving sperm quality characteristics during cryopreservation. The results of the current work demonstrate that using egg yolk-based extender in combination with automatic freezing can be acquired to preserve sperm quality during cryopreservation, whereas soy lecithin-based extender in combination with automatic freezing procedure can be used to control bacterial contamination if sperm quality characteristics are suitably qualified. However, research is needed to evaluate the competence of sperm cells from current treatments on oocyte fertility, conception, and pregnancy rates.