Selection And Optimization Of Diluent Formulation Of Boar Semen Stored At Room Temperature

Success of pig artificial insemination depends largely on the quality of semen. The boar semen is very sensitive to low temperature and the quality of cryopreservation of semen is poorer, therefore semen stored at room temperature is mainly used in the pig artificial insemination. For this, a large amount of research work about boar semen stored at room temperature has been carried out at home and abroad and a variety of diluent formulations have been invented. Along with the pig artificial insemination is widely used in our country, and the quantity demand of semen diluent is increasing. Because a lack of theoretical research about boar semen diluent, there are many inconvenience on the choice of diluent for production and primary breed when facing with the various of diluents. Therefore, inventing good diluent formulations of our country is significant to increase the profit of pig industry and promote the application and popularization of pig artificial insemination technology.To select the good diluent formulation,5kinds of commonly used boar semen extenders were carried out the contrast test and the best diluent formulation was optimized, and then compared the2diluents were prepared by ourselves with the3kinds of middle or long acting diluents in imports, to provide the basis for the choice of diluents and the further research about extenders of boar semen. And the main results as follows:1. The sperm effective survival time in Modena was5.5d, which was the longest in the5diluents and significantly higher than in BTS and I (P<0.05); the sperm effective survival time in BTS and I were higher than in Kiev and IVT(P<0.05); but sperm effective survival time in BTS and I were not significant(P>0.05), which were3.4d and3.9d respectively; and also not significant in Kiev and IVT(.P>0.05), which were2.2d and1.8d respectively. In1～2d of semen storage, the sperm motility, plasma membrane integrity and acrosome integrity in Modena, BTS and I were significantly higher than that in Kiev and IVT(P<0.05), but they were not significantly in Modena, BTS and I (P>0.05); In3～4d of semen storage, the sperm motility, plasma membrane integrity and acrosome integrity in Modena were significantly higher than in BTS and I (P<0.05).2. Modena with3～5g/L BSA can significantly improve sperm motility, effective survival time, plasma membrane integrity and decrease the MDA content (P<0.05), but not significantly affect sperm acrosome integrity and T-AOC (P>0.05). And the Modena with4g/L BSA was the best, the effective survival time was7.5d, after7d of storage, sperm motility, plasma membrane integrity and acrosome integrality were0.54,49%and78%, respectively; the content of T-AOC and MDA were1.03U/mL and17.51nmol/mL, respectively. In conclusion, BSA can improve the quality of boar semen stored at room temperature which optimum addition level in Modena is4g/L.3. The sperm effective survival time in YueFeng-I was11.9d, which was the longest in the5diluents and significantly higher than in Modena+BSA and CXM-MY(P<0.05); The sperm effective survival time in Modena+BSA and CXM-MY were higher than that in Modena and CXM-ZHL (P<0.05); but sperm effective survival time in Modena+BSA and CXM-MY were not significant (P>0.05), which were9.5d and9.9d respectively; and also not significant in Modena and CXM-ZHL (P>0.05), which were6.1d and5.6d respectively. When the storage time of semen was less than6d, the sperm motility, plasma membrane integrity and acrosome integrity in YueFeng-I, Modena+BSA and CXM-MY were significantly higher than in Modena and CXM-ZHL(P<0.05), but not significantly in YueFeng-Ⅰ, Modena+BSA and CXM-MY(P>0.05); When the storage time of semen was more than6d, the sperm motility, plasma membrane integrity and acrosome integrity in YueFeng-Ⅰ were significantly higher than in Modena+BSA and CXM-MY(P<0.05). Furthermore, the pH values of the5extenders were all weakly-alkaline and the pH of the5diluting semen first increased, then decreased and finally rose steadily. And after4d of storage, the pH of diluting semen of CXM-ZHL declined rapidly, but the other four rose steadily.