Comparison of Modified Lake’s Extender for Cryopreservation of Hungarian Giant and Chrabrany Rabbit Sperm

Sperm cryopreservation is the most effective method for the long-term preservation of genetic resources. However, rabbit sperm cryopreservation remains challenging. One of the key factors influencing freezing success is the choice of semen diluent; however, no specific diluent has been established for rabbit semen. In this study, we compared the effectiveness of modified Lake’s diluent and evaluated the cryosurvival of semen from the native Hungarian breed and a native Slovak rabbit breed. Both breeds were subjected to the same static freezing procedure. The following parameters were evaluated: motility, viability, plasma membrane integrity, mitochondrial activity, acrosomal status, and intracellular reactive oxygen species. In fresh samples, viability (93.5% vs. 77.4%), total motility (84.6% vs. 67.0%), and progressive motility (76.1% vs. 47.0%) were significantly higher for the Hungarian Giant than in the Chrabrany rabbit samples. Following cryopreservation, viability (56.4% vs. 43.4%), total (39.2% vs. 20.5%) and progressive (20.6% vs. 8.5%) motility, acrosomal status (72.2% vs. 44.9%) and ROS activity (33.8% vs. 24.6%) were higher in samples from the Chrabrany breed. The results suggest that the modified Lake’s diluent may also be suitable for other rabbit breeds and highlight the importance of developing breed-specific cryopreservation protocols.