Effects Of Glycerin,DMA And Soy Lecithin On Freezing And Cryopreservation Of Semen In Sheep

【Objective】 In order to improve the utilization efficiency of high-quality rams,promote the process of improved breeding in the sheep industry and the economic benefits of breeding,and also to improve the insemination ability of frozen or cryopreserved semen,this study analyzed and compared the effects of different semen protectants on semen cryopreservation and cryopreservation.The best semen freezing and cryopreservation dilutions suitable for sheep were screened out.【Methods】(1)To investigate the effects of glycerol,Dimethylacetamide(DMA)and the combined application of glycerol + DMA on the cryopreservation of sheep semen,and the effects of different ratios of diluent on sperm viability,viability,linear rate,curvilinear rate,acrosome integrity rate,DNA integrity rate and other assays after freezing and thawing of semen,and to determine the optimal diluent for freezing concentration.(2)The cryopreservation test group was used as a cryopreservation test group to analyse the effects of sperm viability,viability,linear rate,curve rate,acrosome integrity rate,DNA integrity rate and other assay indicators,to determine the optimal concentration of cryodilution solution and to arrive at the optimal concentration for the combined application of glycerol and DMA.(3)To investigate the effect of the optimal concentration of glycerol and DMA in combination with different concentrations of soy lecithin(SL)on the cryopreservation of sheep semen,and to explore the effect of different ratios of diluent on sperm viability,viability,linear rate,curvilinear rate,acrosome integrity,DNA integrity and ATP level of sheep semen after cryopreservation.The data were collected using IBM SPSS 20 as a single test.The data were analysed by one-way ANOVA using IBM SPSS 20.【 Result 】(1)During the semen freezing-thawing process,the sperm viability(50.70±4.23 %),viability(64.03±1.98 %),linear rate(20.02±1.78 um/s),curve rate(64.70±5.47 um/s),acrosome integrity rate(46.96±2.05 %)and DNA integrity rate(48.69±5.72 %)of the Tris dilution with 2.5 % glycerol +2.5 % DMA group after rewarming were not significantly different from those of the other groups.46.96±2.05 %),DNA integrity rate(48.69±5.72 %)were not significantly different from 3 % glycerol +2 % DMA(P>0.05);however,they were significantly higher than the other groups(P<0.05).(2)During the cryopreservation of semen,sperm viability,viability,linear rate,curvilinear rate,acrosome integrity,DNA integrity and ATP level were measured at 4 h,12 h,24 h,36 h and 48 h.The addition of 2.5 % glycerol +2.5 % DMA to Tris dilution solution was the most effective for cryopreservation.(3)On the basis of test 2,the addition of 2.5 % glycerol + 2.5 % DMA + 0.5 % SL in Tris diluent achieved the minimum standard for spermatozoa viability(30 %)for all time periods for transfusion.【Conclusion】In summary,(1)the addition of 2.5 % glycerol + 2.5 % DMA to the sheep semen cryobase dilution was significantly more effective than the other groups.(2)The addition of 2.5 % glycerol+ 2.5 % DMA + 0.5 % SL to the sheep semen cryobase dilution at 4 h to 48 h was the most effective for sperm cryopreservation,effectively increasing sperm viability,viability,linear rate,curve rate,acrosome integrity,DNA integrity and ATP levels.