This revised proposal addresses the feasibility of a novel technique in which slaughter house ovaries are used as the source of bovine oocytes which are in vitro matured (IVM) and in vitro fertilized (IVF) with elite semen. Developing embryos are cryopreserved for direct transfer into recipient heifers in a one-step procedure. The current state of embryo transfer relies on fresh collected or cultured material, but is evolving to include direct transfer. There are additional costs associated with synchronizing recipients, or using frozen embryos which require the removal of cryoprotectants (i.e., glycerol) prior to transfer, making direct transfer appealing to the small producer. The proposed course of investigation will evaluate the commercial potential of using a non-co-culture system to create bovine blastocysts from abattoir ovaries and elite semen, loaded into straws containing a novel cryopreservative sequence for liquid nitrogen storage, capable of being thawed and transferred directly into an appropriate surrogate. Data suggests that our system does not produce increased dystocias or calf birth weights, or skews the sex ratio, much different from other co-culture IVM/IVF reports. Success will be judged by non-return rates, and 45, 60 and 90 day pregnancy rates compared to on- farm fresh IVM/IVF controls.Applications:Successful direct transfer commercialization of IVM/IVF bovine embryos will allow beef producers to synchronize the calving date to weather conditions or available feed supplies and allow dairy producers to provide rapid increases in male genetic stock, shorten the days open interval, and increase the likelihood of pregnancy in problem breeders when AI fails due to increased temperature, stress, reproductive pathology, or idiopathic infertility. Once the regulations for embryo exportation are established, the product (frozen embryo in straw) can be readily shipped anywhere in the world. BOMED, Inc. has the capabilities to provide these embryos which could increase the efficiency of beef and milk production, making producers more profitable.
