Embryo Transfer in Thoroughbreds

This is not a sanctioned procedure in the TB

A TB foal has been born from ET and the owner has requested registration (talk about putting a cat amongst the pigeons).

What is Embryo Transfer?

Embryo Transfer (ET) refers to the removal on an embryo from a donor mare and placement into a recipient (surrogate) mare. The recipient continues to carry and ultimately delivers the foal. Readers should note that in ET the genetics of the resultant foal are determined solely by the donor mare and stallion. There is no genetic influence from the surrogate mare. The surrogate mare does have an effect on the size of the foal at birth through the influence of her own uterine size and can effect the foals growth through her milk production. However, ultimately the foals reach their correct size according to their genetics. ET has been used by breeders of almost all breeds for many years (including every racing code except TB's).

The Procedures:
Breeding: In the case in question here the TB mare was bred naturally.
Embryo recovery: The embryo was flushed from Eau D'Etoile's uterus seven days after ovulation (release of the egg).     The flushing techniques involves infusing a buffered saline solution in and siphoning it out again through a small filter. The filter traps the embryo. The filter cup is tipped into a searching dish and the embryo identified under a dissecting microscope. The embryo is then washed and held at room temperature until being transferred into another mare (recipient or surrogate mare). For the procedure to work the surrogate has to be matched quite closely with the donor mare in their reproductive cycles.

Embryo Transfer: The embryos are transferred either surgically (via the flank) or non surgically (through the vagina) into the surrogate mare.

The rules:
The Australian Stud Book specifically prohibits the registration of horses that are produced using new breeding technologies such as embryo transfer. The rules state that the foal must be conceived from natural mating and carried in its natural mother. Embryo transfer is an excepted procedure in most other horse breeds, including breeds that race such as Standardbreds and Quarter Horses.

What has happened:
Eau D’Etoile arrived at the Goulburn Valley Equine Hospital on 31/08/2000.  The purpose of her visit was to ascertain her future as a broodmare and what if any steps could be undertaken to improve her fertility. Her history was that since having a foal removed by caesarean section in 1997 she had not been able to carry a pregnancy to term during the subsequent breeding seasons. During this time she was able to get in foal but continually suffered from early embryonic loss. Examination at the Goulburn Valley Equine Hospital (ultrasound, culture and sensitivity, uterine biopsy etc), revealed that she was an extremely poor candidate to carry her own foal. There were marked degenerative changes to the endometrium that were the direct result of long standing chronic infection and irritation.

The mare was bred to Desert Sun (transported to Eliza Park and bred naturally) on multiple occasions during the 2000 breeding season (first service on 16/09/00 and last service on 28/11/00). She was confirmed in foal on two occasions but was unable to maintain the pregnancies.

Accordingly, Mr. Jim Fleming the owner, was advised if a pregnancy was to be maintained from the mare it may be best to consider embryo transfer. An embryo was recovered from Eau D’Etoile on December 6, 2000 (seven days after ovulation from her last breeding) and transferred into another Thoroughbred mare.

The surrogate mare produced a bay filly foal on Saturday November 17  (2001).

Blood samples sent to Australian Stud Book’s Official Parentage Testing Laboratory for parentage verification and independent parentage validation by the Victorian Institute of Animal Science at Attwood has confirmed the true parents of the foal are as stated (Desert Sun X Eau D'Etoile).

The Issues:

Eau D’Etoile is one of the most genetically valuable mares in our Australian Stud Book . She has produced three group 1 winners (Bint Marscay-won the  STC Golden Slipper, Filante won the AJC Epsom Handicap  and Kenny’s Best Pal won the VRC Australian Guineas). Between them these three thoroughbreds have won in all 10 group races,  In addition a broodmare daughter Temple Fire produced the group 1 winner Stella Cadente.

Mr. Fleming is not looking for any unfair advantage, simply just the opportunity to continue to breed and obtain progeny from his mare. Mr. Fleming believes that not allowing ET foals to be registered is a ‘restriction of his rights to trade’. In addition many believe that not to allow the continuation of genetics that this mare can contribute is a disservice to the Thoroughbred industry. Accordingly he will challenge the Australian Stud Book legally if they refuse to register the foal.

What could happen next?

John Digby, the Keeper of the Stud Book, has advised that he has already referred the matter to the joint proprietors of the Australian Stud Book and to the International Stud Book Committee, warning them that a legal challenge could be mounted. 

Most people believe that ET has some important advantages for the Thoroughbred industry and wish to see it adopted, however many are concerned that once one technique is approved that others requests may follow. 

    1) The simplest result would be for the Australian Stub Book to change the rules and adopt some guidelines for ET that limits the procedure to special reproductive conditions in individual circumstances that are approved on a case by case situation by a panel under the guidance of the Stud Book. Rules would also have produced that limited the procedure to the production of one pregnancy per year and the use of only Thoroughbred mares as the surrogates. 

    2) There have been concerns expressed that if Australia allowed ET foals to be registered that our Thoroughbred horses would not be allowed to race overseas or be recognised by the ISB. To be frank, that is just rhetoric. A similar situation occurred with ET in Standardbreds years ago (1980's) when Standardbreds derived with ET technology in Canada were not given legal status in the USA,  despite being recognised at home. Ultimately they were registered in an appendix until a few years later when ET became legal in Standardbreds in North America because the USTA decided that they could not withstand a restraint of trade clause if legally challenged. 

    3) If the 'Joint Proprietors of the Stud Book' chose to fight the matter in court; then if they win the problem perhaps will go away in the short term. However, as we now live in the 21^st  century and these technologies have been well developed and applied to all domestic species and almost all breeds of horses, how long would you think before another challenge is mounted? Not long one would say. Can we believe that history will judge the decision as wise?. Is this similar to the times (1859) of Charles Darwin introducing "The Origin of Species"? Who remembers his antagonists with anything but amusement? 

    4) The ET ban was introduced before parentage verification with DNA technologies was even developed, and was adopted to protect the integrity of the Stud Book. No one can argue that ET foals will be recorded with correct parentage validation with the most acceptable methods available.

    5) Where will the money come from to fight the case? As the stud book only generates revenues from fees, it can be assumed that any 'fighting fund' will be have to come from increased fees. This challenge may herald a new era. Do the 'Joint Proprietors" have a mandate from the members to spend this money (and the continuation of the above)????

    6) What are Artificial Breeding Technologies anyway? Is it just AI or ET, or should it apply to use of lights to artificially trick mares into cycling earlier, or reproductive hormones to trick mares into ovulation by appointment with the stallion or the common practice of using ultrasound to crush one of a set of twins at ~ 14 days of pregnancy?

    7) Our sources declare that ET in Thoroughbreds has been performed surreptitiously for years and years. Mr. Fleming could have chosen to take the easy road and not declare the progeny as a result of ET. The 'Joint  Proprietors' should be aware that the practice does occur. If they simply fight the matter and win it will drive it all underground again. A few years ago when the Keeper of the Stud Book recognised an unusually high number of foals being born on August 1-3 compared to the breeding dates, he arranged to change the rules to accommodate a sensible approach to the timing of breeding early in the season. The same thing could easily occur again.

    8) Lastly, and most importantly, what will happen if a legal challenge is upheld. In that case one would expect that the Stud Book in this and other countries would never be able to control their breeding conditions. AI, frozen semen, multiple ET even sperm injection could be commonplace within a few years. Would opposing the introduction of limited ET by the 'Joint Proprietors of the Stud Book' be regarded as unwise brinkmanship if the challenge was successful   ???????

Surely, allowing a controlled introduction of ET to the Australian Stud book would have the least long term ramifications.

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