| With the large-scale and intensive development of mutton sheep industry,artificial insemination becomes more and more important.The research and application of liquid storage and cryopreserved ram semen are limitedin our country.Moreover,laparoscopic insemination has not yet been fully applied.Therefore,it is important to improvethe quality of liquid and cryopreserved ram semen and the procedure of laparoscopic insemination.Experiment I:Effect of glutathione on semen quality during liquid storage at 5?.Semens were collected from three Dorper rams and diluted with the diluent supplemented with 0(control),50.0,100.0 and 200 mM glutathione.The result of computer-assisted sperm analysis(CASA)showed that the motility,viability and VCL(curvilinear velocity),VSL(straight linear velocity)and VAP(average path velocity)at 72 h in the 100.0 and 200.0 mM groups were increased significantly.In addition,there were higher sperm plasma membrane integrity and mitochondria activity in the 100.0 and 200.0 mM groups after 72 h storage at 5 ?.Moreover,the higher total antioxidant capacity and glutathione peroxidase,as well as the lower malondialdehyde(MDA)content were obtained in the 100.0 and 200.0 mM groups as compared to the control and 50 mM group(P<0.05).Experiment 2:Effect of body condition on synchronization in the multiparous ewes.Sixty crossbred multiparous ewes with good body condition were randomly divided into two groups:A group and B group respectively.One hundred and eighty crossbred multiparous ewes with bad body condition were randomly divided into two groups:C group and D group respectively.The animals in A and C,B and D groups were injected with 400 IU PMSG and 330 IU PMSG respectively.The result showed the ewes of 400 IU PMSG group had higher estrus rate(P<0.05).In addition,there was higher estrus rate in the ewes with good body condition.Experiment 3:Comparision of conception rate after laparoscopic insemination with liquid storage at 5 ? and frozen-thawed ram semen in different farms.Three hundred and ninety three-year-old Hu ewes with good body condition were collected in Jinshen Wuhe farm.They were randomly divided into two groups;1st group(150 ewes)and 2nd group(240 ewes)for liquid storage at 5 ? and frozen-thawed semen respectively.Moreover,ninety,four-year-old crossbred ewes and three hundred two-year-old Hu ewes with good body condition were collected in Yangqu Huagui farm(3 rd group)and Taigu Baosen farm(4th group),respectively.All ewes were inseminated with the method of laparoscopic insemination.The result showed that the higher conception rate(76,8%vs 65.3%)was obtained in the ewes with liquid storage at 5 ? semen as compared with that using frozen-thawed semen(P<0.05).There was significant difference in the conception rate between farms.Conception rate in Jinshen Wuhe farm was higher than that in Taigu Baosen farm(P<0.05),and conception rate in Taigu Baosen farm was higher than that in Yangqu Huagui farm(P<0.05).Conclusion:Supplementation with 100.0 and 200.0 mM glutathione to diluent can significantly improve the semen quality during liquid storage at 5?.The estrus rate of the 400 IU group was significantly higher than that in the 300 IU goup,and it can be affected by the body condition of ewes.Conception rate is more than 75%and 65%after laparoscopic insemination with liquid storage at 5 ? and frozen-thawed semen.The conception rates influenced by breeds,age and management of farm when the frozen-thawed semen was used. |
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