Abstract：In order to enhance the industrial application of embryos produced by in vitro fertilization(IVF) with sex-sorted sperm, several main factors were investigated in the present study, including cumulus cell removal degree (intact, partial removal and complete removal), different bulls (A~C), volume of IVF drops (30~100 μL) and sperm concentrations(0.3×106~1.0×106/mL). The results showed that (1)The cleavage rate of oocytes with partial removal of cumulus cells (67±4.74)% was significantly higher than that of oocytes with intact cumulus cells (41±2.23)% or complete removal of cumulus cells (37.50±2.88)% (P<0.05); (2)The cleavage and blastocyst rates of oocytes fertilized with sex-sorted sperm of bull B [(61.25±5.78)%, (26.53±3.31)%] were significantly higher than those of bull A [(42.5±3.45)%, (17.65±3.65)%] and C [(30±2.62)%, (16.67±2.36)%] (P<0.05); (3)The cleavage and blastocysts rates of oocytes fertilized in 50~100 μL drops had no significant difference(60±3.54)%~(64.17±3.04)% and (20.41±4.33)%~(23.38±4.47)% (P>0.05), but significantly higher than those in 40 μL[(48.33±2.89)%, (13.79±2.02)%] or 30 μL [(33±2.74)%, (12.12±3.73)%](P<0.05);(4)The cleavage and blastocyst rates of oocytes fertilized with a sperm concentration of 0.5×106~1.0×106/mL showed no significant difference(62±4.12)%~(68.75±4.64)% and (22.58±2.17)%~(27.27±3.49)% (P>0.05), but were significantly higher than those with 0.3×106/mL[(38.75±3.58)%, (16.13±3.46)%] group(P<0.05). The results indicate that partial removal of cumulus cells and the selection of appropriate bulls combined with reasonable decrease of volume of drops and sperm concentration contribute greatly to increasing the efficiency of IVF with sex-sorted sperm, meanwhile decreasing the production cost of sexed embryos.
