Studies On In Vitro Fertilization In Bovine

In order to promote efficiency of IVF in cattle.the systematic research was done from three main aspects-IVM IVF and IVC,using the oocytes from ovaries collected in slaughterhouse.The results were as follows:1.According to integrality of cumulus cell.the oocytes were performed for IVM respectively.The results showed the oocytes without cumulus cell had significantly lower cleavage rate and blastocyst-morula rate than the oocytes with cumulus (P<0.01),but a few fertilized oocytes can developed to morula after co-cultured with cumulus cell.Besides,it was found that the more integral cumulus cell was,the higer the blastocyst-morula rate was for oocytes with cumulus cell.This indicated cumulus cell is important for IVM of oocytes.2.BFFs of different concentration,instead of FBS.were added into maturation media for IVM of oocytes.The results showed there was no significant difference between 10%bFF and 10%FBS groups in maturation rate (P>0.05) ;the maturation rate was reduced significantly in the medium with other concentration (p<0.01) .The results indicated bFF of proper concentration dose not affect maturation rate of oocytes but other concentration3.GFFs of different concentration,instead of FBS,were added into maturation media for IVM of oocytes. The results showed there was no significant difference between 10%gFF and 10%FBS groups in maturation rate;however the maturation rate in orther groups were significantly decreeased(P<0.0l).This indicated gFF has no specie-associated effect on oocytes of bovine and proper concentration dose not affect maturation rate of oocytes4.COM was patially or entirely peeled before fertilization.The results showed the blastocyst-morula rate was significantly lower in the group without COM than other groups (P<0.01) after fertilized.This indicated COM do not affect fertilization of oocytes but affect embryonic development after fertilization.5.Both oocytes and sperm were put in different temperature for fertilization.The results showed the cleavage rate,blastocyst rate and blastocyst rate of D7 in 39℃ were higer than those in other temperature.This indicated the temperature of fertilization takes important effect on fertilization of oocytes,embryonic development after fertilization and developmental speed of embryos.6.Oocytes without cumulus cell in different stages after fertilization were thansfered it in monolayer to culture continuously.The results showed the blastocyst-morula rates in the groups incubated at 24h,36h and 48h were significantly higher than those in other groups(p<0.01).Blastocyst-morula rate was the highest when incubated at 24h and 48h.This indicated the time of peeling cumulus cell affects embryo development significantly and the proper time is 24~28h after fertilization.