Study On The Key Technique Of Jiaxian Red Cattle Embryo Genic Library Establishment

Establishment Embryo genic library is an economical and effective way to conserve livestock breed.Estrous synchronization,superovulation and freezing conservation are key technique for embryo genic library foundation.Since 1940's,with the improvement of leechdom,programme and appliance,the embryo transfer technique has been constantly developed.Especially,its application in dairy cow has been driven to maturity.However,the research and application in yellow cattle genic library establishment are limited.To strengthen the conservation of endemic yellow cattle resources in Henan province,the key techniques,that's estrous synchronizing,superovulating and embryo freezing,technique,were systematically studied with Jiaxian red cattle as object.Sixty-seven head-time Jiaxian red cattle were superovulated.The effects of different estrous synchronization protocols on estrous synchronization ratio were studied with emphasis and effects of factors,such as medicine,dosage,season and repeated times,on superovulation were discussed.Meanwhile,different freezing regents and different glycerol concentration were investigated for their protective effect.This study were to select proper estrous synchronization,superovulation and embryo freezing methods or protocols of Jiaxian red cattle and provide scientific basis for embryo genic library foundation of Jiaxian red cattle as well as other endemic yellow cattle breed.The results were listed as following.1.After Comparison of four estrous synchronization protocols,the estrous synchronization ratios of protocolⅡandⅣ,injection of prostaglandin(PG) right after CIDR withdrawal and twice injection of PG,were 73.1 and 76.7%, respectively,which were Significantly higher(P＜0.05) than that of once injection of PG(protocolⅢ)(52.4%),and no PG injection(protocolⅠ)(60.9 %).2.Sixty-seven head-time Jiaxian red cattle were superovulated using follicle-stimulating hormone(FSH) from domestic or imported,in which 44 head-time were effectively superovulated.As a whole,the average count of luteiniz(CL),embryos and available embryos were 13.72,6.83 and 4.28 per head,respectively.3.The source and dosage of FSH have no significant effect on average CL (P＞0.05).The average embryoes and available embryoes of imported(Canada) FSH at the dosage 300 mg per head were,respectively,8.86 and 5.98,which were significantly higher than that of dosage 280 and 320mg per head(6.32, 3.05 and 6.56,4.12,respectively)(P＜0.05).The average embryoes and available embryoes of domestic(Ningbo) FSH at the dosage 320 mg per head were,respectively,8.12 and 5.46,which were significantly higher than that of dosage 280 and 300mg per head(5.55,2.76 and 6.32,3.77,respectively) (P＜0.05).4.After integrating the results of three imported and domestic FSH dosage,the average CL,average embryo and available embryo were 13.89 and 13.41,6.93 and 6.74,4.42 and 3.95,respectively.It was indicated that there were no significant difference between imported and domestic FSH in superovulation.5.There were 6 head-time multiparous and 38 head-time finishing Jiaxian red cattle superovulated.The results showed that the average CL and embryo of multiparous cattle(14.54 and 8.72,respectively) were markedly higher than that of finishing cattle(P＜0.05),while no statistical difference were observed in average available embryo(P＞0.05).6.In summer and autumn(May to October) as well as winter and spring (November to April),twenty-three and twenty-one Jiaxian red cattle were superovulated,respectively.The results showed that season had no significant effect on average CL(P＞0.05).Higher average embryo and available embryo were obtained in winter and spring(7.23 and 6.51) than in summer and autumn (4.57 and 2.90)(P＜0.05).7.At interval of 70 days,the average CL of once,twice and thrice superovulating treatment were 14.30,13.12 and 12.23,respectively,and the average embryo and available embryo were 7.31,6.52 and 6.45 as well as 4.56,4.15 and 3.96, respectively.It can be indicated that the time of superovulating treatment had no effect on the above three index(P＞0.05).8.The growth ratios after frozen of protective agent,1.5 M ethylene glycol(EG) and 2.0 mol/L glycerol,were both 85.7%,which were higher than treatment of EFS40(71.4%)(P＜0.05).9.Different concentrations of glycerol were used for 7-day morula or blastula regular freezing embryo.The growth ratios after frozen of 1.5,2.0,2.5 and 3.0 mol/L were 42.9,85.7,71.4 and 28.6%.The growth ratios after frozen of 2.0 and 2.5 mol/L were significantly higher than that of 1.5 and 3.0 mol/L.