The interesting evolution of embryo transfers
Of the nearly 2,000 embryo transfer foals registered since 1996, 326 have earned in excess of $100,000.
by Murray Brown
Recently, a very knowledgeable friend told me that he would never buy a yearling conceived by embryo transfer and raised by a recipient mare.
“Why?” I asked. “In terms of genetics, there is no reason why the foal conceived using embryo transfer technology should not be the same as one bred and raised in the normally accepted manner?”
His answer was that the buying of yearlings is enough of a crapshoot as it is, why bring another unknown into the equation? He felt that we do not know enough about the process and its results.
I thought that a column on the subject might help to fill in a few of the blanks.
Most of the data furnished in this story was produced through the kindness of T.C. Lane, the United States Trotting Association’s chief operating officer.
The first year that embryo transfers (ETs) were accepted for registration by the USTA and Standardbred Canada was 1996. Since then, there have been a total of 1,971 ETs registered, an average of just about 66 per year. Of that number, 326 have earned in excess of $100,000 and 36 have earned over $500,000. Those numbers do not necessarily give the complete picture, since among them are yearlings, 2-year-olds and undoubtedly some 3-year-olds and older horses who will doubtless gain entry into those earnings areas.
In recent years, most specifically among yearlings of 2024, there were 84 registered. Of those, 22 were sold at the two major yearling sales in Lexington and Harrisburg. According to the respective catalog pages, there were eight ET yearlings sold in Lexington and 14 in Harrisburg. Here’s something that somewhat surprised me. Of those 22 yearlings, 10, almost half, were sold by and raised at Hanover Shoe Farms. Why were so many raised by only one farm, albeit the second largest in terms of number of foals registered?
The farm that produces the largest number of registrations annually is Winbak Farms. If asked why Hanover dominated the numbers, my guess would come down to one word — economics. Simply put, raising yearlings using embryo transfer is not cheap, nor is it necessarily easy. There are several factors including the cost of the lab work involved, the ability and expense involved in acquiring recipient mares, and the expenses involved in maintaining two instead of one broodmares.
For a farm like Hanover much of that extra expense is negated by having the means in house to achieve the necessary ends. They are able to do most of the necessary lab work in securing the embryo and in transferring it to the recipient mare in house. They have the personnel with the ability to do this. Moreover, they have, mostly because of their large numbers, been able to come up with a pool of potential recipients, both in mares with who it isn’t financially feasible to raise yearlings for the market, or with an occasional filly who for whatever reasons is unfit for sale to use as recipients. They likely have these mares at their disposal for little cost in being able to use them for this purpose.
I asked myself, in which situations is breeding using ET an advantage? These come immediately to mind:
• 1 — Whether you believe or do not believe in the procedure, in almost all cases an ET foal is better than no foal at all. If you can raise a financially viable yearling out of a mare who, for physical reasons is unable to carry a foal to term, then you are in a much better situation than you would be if you were unable to raise a foal out of that mare at all.
• 2 — If your mare is in poor physical condition so that raising a foal out of her could be harmful to that foal and extremely stressful to the mare in terms of nutrition and proper exercise for both. Let us suppose, you had a mare that was crippled. Chances are that if she had a foal, it would be compromised in terms of getting enough exercise. Your foal’s chances of getting a proper upbringing would be enhanced by its being raised by a young, vibrant mare or even by an older mare who is in good physical condition.
Which brings me to another question. How many of the people looking at ET yearlings ask about the recipient mare that raised that yearling? Without knowing the answer to the question, I would guess not too many. If you don’t ask, chances are you will not know.
In the early years of ETs, I recall many of the recipient mares being big draft types who were not inclined to exercise too much. Of course, their foals would follow suit. I heard complaints voiced because of the situation. In recent years, I believe this has changed somewhat. The recipient mares are now more likely to be healthy, vibrant and not of the lazy type.
• 3 — If the mare was still in training and its owner wanted to both race and raise a foal from her. Such a situation happened with the 2018 Hambletonian winner Atlanta.
In 2021, when Atlanta was preparing to race, an embryo by Muscle Hill was harvested from her. This resulted in producing the stakes winning filly Deja Blu ($260,502) conceived that same year, while Atlanta continued racing. In looking at the breeding history of Atlanta, one notices that she failed to produce foals in the two subsequent years although being bred naturally. Just a coincidence? Maybe. Her next foal, a 2026 yearling is a filly by Tactical Landing.
• 4 — If a mare is due very late, it could become an ET donor with the intent of getting her on a better schedule, enabling her to begin producing earlier foals. For example, a mare is due in late June, and instead of breeding her back at the likely earliest in late July, an embryo out of her is harvested to a recipient mare. Instead of regularly producing late foals, she is now open to being bred early the following season and then is going on to a more amenable schedule.
In conclusion, here are the 12 highest earning racehorses having been conceived by ET and raised by recipient mares. While the richest one, Invitro, is in the Canadian Horse Racing Hall of Fame, her time was more than 20 years ago. That means International Moni, the 12th horse on the list, is likely the best known today. Several of the foals from his dam, the incredible Moni Maker, were ETs. They are already well on the way to producing a remarkable branch of one of the breed’s greatest trotting families.
1. Invitro – $1,938,077
2. Ginger And Fred — $1,928,158
3. Define The World — $1,654,115
4. Sapphire City — $1,490,475
5. Nob Hill High — $1,110,703
6. Domitian Hanover — $1,090,514
7. Fred And Ginger — $1,053,740
8. Rockapelo — $940,311
9. Eighteen — $910,224
10. Chin Chin Hall — $$878,320
11. Raised By Lindy — $796,746
12. International Moni — $775,463
