Improving The Blastocyst Development Rate Of Bovine Embryo In Vitro

In order to increase the rate of bovine embryo blastocyst development in vitro, different estrous cycle serum of goats was used in culturing embryos. The serums was collected among the estrous cycle.DO,D2,D4 and D7(the day of estrous beginning is D0)goat serum, then sterilired and stored. The result shows the effect of the different serum on the cleavage rate of parthenogenetic embryo is not significant, but the blastocyst rate is 29.5%,32.4%,33.9% and 41.3% respectively, D7 serum can significantly increase the blastocyst rate(P<0.05)and expanded and hatched embryos come earlier.DO serum can raises the cleavage rate of IVF embryo significantly(P<0.05), but cannot improve the blastocyst formation obviously. It shows that it has the discrepancy between the in vitro developmental competence of the parthenogenetic and IVF embryo, D7 serum was beneficial to later development of bovine embryos. After culturing 3 d without serum, the addition D7 serum can heighten the blastocyst rate of IVF embryo, percentage of blastocyst was 42.9%. This is a better culturing method for culturing embryo in vitro.In order to define the effect of the dominant bFF on oocyte maturation in vitro,0%,20%,30% and 50% follicular fluid was supplied to maturation medium before parthenogenetic activation or in vitro fertilization and culturing in CRlaa.Result:cleavage rate is not significantly discrepant in the parthenogenetic group ,but the rate of blastocyst is better in the bFF group than the control;Along with the increase of bFF,in IVF group , cleavage and blastocyst rate decreases.In 10% bFF , blastocyst rate is 47.1%(P<0.05) and 38.0%.Conclusion:addiction of 10% bFF is beneficial to oocyte cytoplasmic maturation.In this study, determination of culture condition in embryo development in vitro is ready to programmed embryo production. Experiment contents ;(1) The effect of the time of fertilization on the cleavage and developmental capacity.(2) the effect of the time of oocyte maturation on development;(3) the effect of the different embryo culture media on embryo development;(4) the effect of co- culture with the cumulus cell on embryo development.(5)the effect of the different volume of culture media on embryo development.Resulta 12h and 24h in fertilization is not different significantly on embryo cleavage,but fertilizaition 24h is better than 12h on embryo development;b Time of oocyte muturation (24h and 32h) is different significantly on cleavage (58.7% and 31.3% respectively P<0.05) c embryo culture media (CR1+BSA and SOF+BSA) is almost similar on embryo development,but these media has better effective than protein -free media.d cumulus co-culture is significantly capable to support the development of bovine embryos to blastocysts rate of 39.1%(P<0.05).e Culture media volume(0.5ml and 2ml) is important on embryo development and is better than O.lml,the blastocysts rate is 36.4%,32.9%;and 6.8% (P<0.05) respectively.Conclusion: sperm-oocyte interaction 24h;oocyte maturation 24h; culture media being CRl+BSA;cumulus co-culture and 0.5ml culture media is a better culture system.