[Reproductive medicine in transition: new developments in embryo transfer].

The research article discusses the progress made in the field of reproductive medicine, specifically focusing on embryo transfer (ET) and how it has been successfully applied to cattle, horses, sheep, goats and other captive species. It highlights the improvements made in transvaginal ovum pick up, in vitro production, and cryopreservation to enhance the application of ET.

Embryo Transfer and its Commercial Application

• The practice of Embryo Transfer (ET), which involves moving an embryo from a donor to a recipient, has been successfully applied in a range of animals including cattle, horses, sheep, and goats. In particular, this technique has been commercially established in cattle. In fact, in 1994, over 100,000 bovine embryos were transferred in European countries, attesting to the widespread use and important role of ET in animal agriculture and potentially in conservation of endangered species.

Developments in Techniques Related to Embryo Transfer

• Significant progress has been made in the realms of transvaginal ovum pick up (OPU), in vitro production (IVP) and cryopreservation, all of which greatly facilitate the application of ET.
  • OPU refers to the retrieval of oocytes (immature eggs) from the ovaries, which can then be used for in vitro fertilization to produce embryos.
  • IVP involves fertilization of these retrieved oocytes occurring outside of the living organism—in a petri dish—thus producing embryos.
  • Cryopreservation is the process of preserving biological constructs at very low temperatures, which allows for the storage of the generated embryos until they are ready to be transferred.

The Advantages of Direct Transfer

• Direct transfer, as opposed to traditional means of ET, simplifies the procedure considerably by eliminating the need to synchronize the recipients’ estrus cycles – the stage where the female is ready to accept an embryo.
• Furthermore, it allows for individual transfers, implying a higher degree of control and precision in the application of ET.

Support for Practitioners

• To support practitioners performing embryo transfer, ‘Veterinary Society for Embryo Transfer’ was established in Switzerland in 1995.
• This organization may provide practitioners with technical support, updated knowledge, and networking opportunities to improve their proficiency in ET and consequently, lead to even more successful outcomes.