Studies On The In Vitro Maturation And In Vitro Fertilization Of Follicula Oocytes In Nanyang Cattle

As one of five excellent breeds of cattle in China, Nanyang cattle have great value in breed conservation and in breeding. It is a new approach for breed conversation of Nanyang cattle via foundation of Nanyang cattle embryo gene pool by in vitro maturation(IVM) and in vitro fertilization (IVF)of follicular oocyte. So far, there has not been report about systematic research on (IVF) of Nanyang cattle. In this study, ooctytes of Nanyang cattle were collected from 2 to 8 mm follicles in surface of ovary of butchered Nanyang cattle, and the oocytes were used for in vitro maturation (IVM), in vitro fertilization(IVF) and in vitro culture (IVC), the objective is to explore factors that affected IVF of oocytes of Nanyang cattle and establish a feasible program to in vitro production of embryos in Nanyang cattle. The results were as follows:1.The number of cumulus cell layer around oocytes influenced IVM and IVF of oocytes. The results showed that the first polation rate(87.5%) ,cleavage rate(74.2%) and blastocyst rate (35.1%)of oocytes rounded by 2—8 layers of cumulus cells were obviously higher than groups with more than 8 layers and less than 2 layers. The group with less than 2 layers had higher first polation rate(67.5%) ,cleavage rate(48.8%) and blastocyst rate(23.8%) than group with more than 8 layers and group of nude oocystes. The group of nude oocytes performed worst, blastocyst rate was zero.2. 10% ocs was added to culture medium and fisrt poleation rate (87.5%), cleavage rate(74.2%), blastocyst rate(35.1%) of oocytes were significant different (P<0.01)from groups that added FBS and BSA respectively. The FBS group and BSA group had dramatic discrepancy in first poleation rate ,cleavge rate and blastocyst rate(P<0.01). The first poleation rate (52.5%),cleavage rate (32.9%)and blastocyst rate(15.6%)in BSA group were the lowest.3.Mature medium added with 0% (control group, 10%FBS), 10%BFF, 20%BFF, 30%BFF, and 40%BFF respectively were compared in the effect on IVM, the results showed that oocytes in 10%BFF group and 20%BFF group were significantly higher in first poleation rate (82.5%,85.0%),cleavage rate (76.9%,77.9%)and blastocyst rate (30.1%,35.8%)than contrast group, 30%BFF group and 40%BFF group. When concentration of liquid in oocytes came to 30% and 40%, first poleation rate ,cleavage rate of oocytes declined 42.5,75.0 and 44.9,64 percent compared to 20% group, but blastocyst rate in 30% group increased 5.3 percent than 20% group.4.FSH, LH and E₂ were added to mature medium respectively, the first poleation rate, cleavage rate and blastocyst rate of oocytes between the three group had no significant difference(P>0.05) when compared with control group. E₂+FSH+LH group had no effect on...