Effect Of Different Protocols On Buck Semen Liquid Storage

The best way for semen storage is cryopreservation, which has been used for bull semen storage and artificial insemination successfully. Cryo- preservation of bull semen has been commercialized for many years. However, the cryopreservation for goat semen is not successful. Although the motility of goat post-thaw semen is up to 30%, the fertility rate and conception rate are much lower than that of fresh semen. In order to prompt the usage of artificial insemination on goat, it is necessary to find a long-time liquid storage protocol at present. The present investigation is to investigate the relationship between motility and pH, the effect of extenders in different pH, the effect of egg yolk coating and the effect of half extender replacement on liquid storage. five healthy adult Lubei white bucks were used for semen collection. And semen was diluted by mZAP or MES extender. The results are summarized as follows:1. With the time prolonged the extender pH depressed after semen diluted by mZAP. The relationship between motility change and pH change is high. The correlation coefficient is 0.8837 without coating and 0.8156 with coating respectively.2. The spermatozoa with egg yolk coating can tolerate lower pH than those without egg yolk coating.3. The motility of semen with egg yolk coating diluted by mZAP extender in pH6.25 without extender replacement was up to 30% after 16 days'storage,which was better than those diluted by mZAP extender in pH6.04.4. The motility of semen diluted by MES extender was significantly higher than that in mZAP extender when the initial pH were both in pH6.25 during 8-10 days'storage, but there was no difference at membrane intact and acrosome intact.5. The better way for semen storage is extender replacement compared the no extender replacement when diluted by MES extender in pH6.25 without coating.The results show that the pH depression in extender affects the motility harmfully. The semen with egg yolk coating can tolerate lower pH than those without egg yolk coating. Extender replacement during semen storage can prolong storage time efficiently . The motility of semen with egg yolk coating diluted by mZAP extender in pH6.25 without extender replacement was up to 30% after 16 days'storage.