Abstract: The purpose of the experiment was to analyze the influencing factors of bovine superovulation-in vivo embryo production, and to provide basis for improving in vivo embryo production efficiency and optimizing in vivo embryo production process. Holstein and Simmental cattle young cows with normal reproductive performance at 14~15 months of age were subjected to superovulation treatment, and different breeds and types of Follitropin beta, the superovulation effect of repeated supersteak was compared with that of different operators. The mean number of recovered embryos and the mean number of effective embryos in the Simmental cattle were higher than those in the Holstein, with significant difference (P<0.05) and no significant difference (P>0.05), respectively. The effective embryo rate of Holstein was higher than that of Simmental cattle, but the difference was not significant (P> 0.05) The average embryo, effective embryo and effective embryo rate of the imported Follitropin beta treated Simmental cattle were significantly higher than those of the domestic Follitropin injection group (P<0.05) . There was no significant difference in the average number of embryos obtained from Follitropin beta imported from different countries (P>0.05) , and no significant difference in the average number of embryos obtained by technicians from different countries (P>0.05) , there was no significant difference in the number of effective embryos and effective embryo rate between technician No. 1 and technician No. 2(P>0.05) , but it was significantly higher than that of technician No. 3(P<0.05) The average number of embryos obtained by superovulation was 7.0 and 7.7, the average number of effective embryos was 2.7 and 3.2, the effective embryo rate was 38% and 41% , respectively, the effect of the second superovulation was better than that of the first, but there was no significant difference between the two superovulation (P>0.05) .Superovulation and in vivo embryo production are affected by various factors such as donor breed, superovulation frequency, source of Follitropin beta, technical level of operators, etc. , the optimal superovulation scheme is found by integrating various factors.

Key words: Holstein cattle, Simmental cattle, Superovulation, In vivo embryo, Influencing factors