Introduction

• The use of embryo transfer was first documented in 1890 when two offspring were produced following embryo transfer in a rabbit.
• Initially embryo transfer in cattle was undertaken surgically, but since the mid 1970’s this has been replaced by a nonsurgical recovery technique.
• Since its global commercialization, over forty years following the ability to cryopreserve (freeze) embryos and achieve pregnancies, embryo transfer has been utilized to propagate superior genetic lines of cattle through the production of multiple offspring within the same year, often using different sires.
• In principle the process involves the generation of a reference heat in the donor animal, administration of exogenous follicle stimulating hormone (FSH) to cause superovulation, insemination at the correct time and nonsurgical recovery of the embryos 7 days.
• After grading, embryos can be either transferred fresh into recipient animals, whose cycle is synchronized to that of the donor animal, or frozen for future use or trade.

Superovulation

Embryo collection

Embryo grading

Cryoprotection of embryos

Fresh transfer to recipients

Donor management

Recipient management

Embryo manipulations

Further Reading

Publications

Refereed Papers

• Recent references from PubMed and VetMedResource.
• Mikkola M & Taponen J (2017) Embryo yield in dairy cattle after superovulation with Folltropin or Pluset. Theriogenology 88, 84-88 PubMed.
• Moore S G & Hasler J F (2017) A 100-Year Review: Reproductive technologies in dairy science. J Dairy Sci 100, 10314-10331 PubMed.
• Phillips P E & Jahnke M M (2016) Embryo Transfer (Techniques, Donors, and Recipients). Vet Clin Food Anim 32, 365-385 PubMed.
• Gabriel A B & Mapletoft R J (2014) Historical perspectives and recent research on superovulation in cattle. Theriogenology 81, 38-48 PubMed.
• Hasler J F (2014) Forty years of embryo transfer in cattle: A review focusing on the journal Theriogenology, the growth of the industry in North America, and personal reminisces. Theriogenology 81 , 152-169 PubMed.
• Machaty Z, Peippo J, Peter A (2012) Production and manipulation of bovine embryos: Techniques and terminology. Theriogenology 78, 937-950 PubMed.
• Smith A K (2009) Embryo Transfer - Opportunities for Vets and Scientists. Cattle Practice 17 (1) ,16-25.

Other sources of information

• The Bovine Embryo (Collection, Production and Transfer) Regulations 1995. https://www.legislation.gov.uk. Accessed 10/05/2018.