Equis ISSN 2398-2977

Embryo Transfer

Contributor(s): Madeleine L H Campbell, John Dascanio, Graham Munroe

Introduction

  • Collection of a fertilized oocyte or embryo from a donor mare and transfering it to the reproductive tract of a synchronized recipient mare.
  • First recorded in the 1970s for use in the horse.
  • Not all breed authorities will allow embryo transfer, particularly the Thoroughbred (Jockey Club).
  • Considerable organization, veterinary attention and expense are involved.
  • The technique has become increasingly popular in recent years, particularly since non-surgical transfer became the norm.

Reasons for Embryo Transfer

Increased production from valuable mares

  • Increase the number of foals it is possible to breed from a mare per year or lifetime.

May not be possible to register more than one foal per year in some breed associations.

  • Production of a foal from performance mares whilst still performing.
  • Management of mares which are unable to carry a foal safely to full term themselves, eg due to previous colic surgery/a ventral rupture.
  • Some subfertile mares with specific problems, eg cervical injuries, may be good candidates for embryo transfer. However, recent research shows that transferring embryos from old mares with a history of early embryonic death   Abortion: early embryonic / fetal death  , into young recipients did not increase foaling rates, ie embryo transfer is not a useful technique in old mares with embryonic failure, because the fundamental problem is at the level of the aged oocyte.
  • Generally, subfertile mares have lesser embryo recovery rates than normal mares, and their embryos have a higher failure rate post-transfer than embryos of normal mares.

Assessment of fertility

  • Occasionally used as a means to assess fertility of mares or stallions particularly in the latter case where semen is to be processed   Semen: cryopreservation  .

Selection of participants

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Synchronization of ovulation

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Insemination of the donor mare

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Embryo recovery

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Embryo transfer

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Further Reading

Publications

Refereed papers
  • Recent references fromPubMedandVetMedResource.
  • Campbell M L H (2014)Embryo transfer in competition horses: Managing mares and expectations. Equine Vet Educ26(6), 322-327VetMedResource
  • Campos-Chillon L F et al(2009)Vitrification of early-stage bovine and equine embryos. Theriogenology71(2), 349-354PubMed.
  • McCue P M, Patten M, Denniston D D, Bruemmer J E & Squires E L (2008)Strategies for using eFSH for superovulating mares. J Equine Vet Sci28, 91-96VetMedResource.
  • Squires E L, Carnevale E M, McCue P M & Bruemmer J E (2003)Embryo technologies in the horse. Theriogenology59(1), 151-170PubMed.
  • Wisher S & Allen W R (2004)An improved method for nonsurgical embryo transfer in the mare. Equine Vet Educ16(1), 30-44VetMedResource.
  • Squires E L et al(1999)The current status of equine embryo transfer. Theriogenology51(1), 91-104PubMed.
  • Camillo F et al(1997)The use of early pregnant mares as embryo recipients. Equine Vet J Suppl25, 77-79PubMed.
  • Seidel G E Jr (1996)Cryopreservation of equine embryos. Vet Clin North Am Equine Pract12(1), 85-99PubMed.
  • Philpott M (1993)The dangers of disease transmission by artificial insemination and embryo transfer. Br Vet J149(4), 339-369PubMed.
  • Katila T et al(1989)Embryo transfer in subfertile mares. Acta Vet Scand30(3), 329-333PubMed.
  • McKinnon A O et al(1988)Equine embryo transfer. Vet Clin North Am Equine Pract4(2), 305-333PubMed.
  • Sirois J et al(1987)PGF-2 alpha release, progesterone secretion and conceptus growth associated with successful and unsuccessful transcervical embryo transfer and reinsertion in the mare. J Reprod Fertil Suppl35, 419-427PubMed.
  • Juliano M F et al(1985)Effect of age of equine embryos and method of transfer on pregnancy rate. J Anim Sci60(1), 258-263PubMed.
  • Squires E L et al(1982)Factors affecting reproductive efficiency in an equine embryo transfer program. J Reprod Fertil Suppl32, 409-414PubMed.
  • Douglas R H (1982)Some aspects of equine embryo transfer. J Reprod Fertil Suppl32, 405-408PubMed.
  • Imel K J et al(1981)Collection and transfer of equine embryos. JAVMA179(10), 987-991PubMed.

Other sources of information

  • Equine Embryo Transfer IV.Proceedings of the 4th International Symposium on Equine Embryo Transfer. Reims, France, 16-18 January,1997. Equine Vet J Suppl25, 6-112.


ADDED