Study Of OPU-derived Yanbian Yellow Cattle Embryos Following Controlled Slow Freezing

Yanbian cattle are five of China’s excellent cattle breeds.However,due to the low level of industry,the shortage of cattle sources has become increasingly serious in recent years,making it difficult to meet market demand.This article explores the use of advanced technologies such as embryo freezing and embryo transfer,to efficiently expand breeding and breeding in order to solve the problem of cattle source.Embryo freezing is a technique that uses special low-temperature protection measures and cooling procedures to achieve long-term stable storage of embryos at ultra-low temperature,and to restore normal physiological functions after thawing.Embryo freezing technology can save high quality embryos in time and avoid waste of embryos.Embryo freezing technology breaks the time and space limitations of embryo transfer,and is conducive to the promotion and application of embryo transfer.It has great significance for accelerating the large-scale breeding of fine breed livestock and is an important part of embryo engineering technology.This experiment takes Yanbian yellow cattle OPU embryos as the research object,and aims to explore the freezing method suitable for Yanbian yellow cattle industrial applications.The following results are obtained:1:The effect of glycerol concentration on the programmed freezing of OPU embryos in Yanbian yellow cattle.When glycerin was used as a cryoprotectant to program the frozen Yanbian yellow cattle OPU embryos,the survival rate and hatchability of frozen Yanbian yellow cattle OPU embryos were highest when the glycerol concentration was 2.0 mol/L,which were 70.10 ± 8.70%and 36.56± 3.34%,respectively.There was no significant difference with 1.5 mol/L,2.5 mol/L and 3.0 mol/L(P>0.05),which was significantly higher than that of 0.5 mo/L and 1.0 mol/L groups(P<0.05).There was no significant difference in survival rate and hatchability between the 0.5 mol/L group and the 1.0 mol/L group(P<0.05),and the two groups were significantly lower than the other four groups(P<0.05).2:The effect of ethylene glycol concentration on programmed freezing of OPU embryos in Yanbian yellow cattle.When ethylene glycol was used as a cryoprotectant to program the frozen Yanbian yellow cattle OPU embryos,the survival rate and hatchability of frozen Yanbian yellow cattle OPU embryos were highest when the ethylene glycol concentration was 1.5 mol/L,which were 61.52 ± 7.84%and 29.09±1.58%,respectively.It was significantly different from the 0.5 mol/L group(P<0.05),but not significantly different from the 1.0 mol/L group,the 2.0 mol/L group,the 2.5 mol/L group,and the 3.0 mol/L group(P>0.05).3:The effects of cryoprotectant types on the programmed freezing of OPU embryos in Yanbian yellow cattle.There was no significant difference between survival rate and hatchability of frozen embryos frozen in glycerol(2.0 mol/L)and ethylene glycol(1.5 mol/L)when cryopreserved OPU embryos in Yanbian yellow cattle(P>0.05),But glycerol is better than ethylene glycol.Therefore,glycerin was selected as the cryopreservative for the frozen frozen OPU embryos of Yanbian yellow cattle.4:The effect of different equilibration time on the programmed freezing of OPU embryos in Yanbian cattle.With glycerol(2.0 mol/L)as the cryoprotectant,the survival and hatching rates of frozen embryos were highest when the equilibrium time was 15 min,which were 66.77 ±3.18%and 36.56± 3.34%,respectively.It is significantly different from the 5 min group and the 25 min group(P<0.05),but not significantly different from the 10 min group and the 20 min group(P>0.05).5:The effects of different developmental stages of embryos on the programmed freezing of OPU embryos in Yanbian yellow cattle.With glycerol as a cryoprotectant,the survival rate of expanded blastocysts(68.69 ±3.50%)and hatchability(37.37±7.00%)in frozen Yanbian OPU embryos were higher than the survival rate of blastocysts(60.74 ± 5.60%)and hatchability(31.85±8.98%),but the difference between the two groups was not significant(P>0.05).In conclusion,the test results show that the use of 2.0 mol/L glycerol as the programmed cryoprotectant for OPU embryos in Yanbian yellow cattle is the best;the optimal equilibrium time in the cryoprotectant is 15 min;the effect of frozen Yanbian cattle OPU expanding blastocysts is better.