For investigating PB1 extrusion of cattle’s oocytes under different component concentrations of culture solution,culture methods in vitro and oocytes derivation,COCs suctioned from abattoir-derived ovarian follicles were cultured under different situations.Results showed that the culture conditions in vitro promoted PB1 extrusion of cattle’s oocytes significantly(P<0.05).The optimized components added in the culture medium were 10 μg·mL-1 FSH,10 μg·mL-1 LH,1.0 μg·mL-1 17-β E2 and 33.0 μg·mL-1 sodium pyruvat...