The Business Side of Things

As I promised, I would like to discuss this web site I found which has facilities in Europe and Canada. The site advertises that a perspective client can purchase a foal from any combination of mare and stallion. When I read this it made me very curious about how they do this since it is not common that anyone would be able to buy a foal from a mare that they did not own. In my curiosity I clicked on the stallions available. The process of buying frozen semen is not uncommon, and the facility I worked at did not own the semen there but would store it and ship it out to mare owners that requested it and paid the stallion owner (who would also legally own the semen). The semen from Equine Embryos is on a pregnancy guarantee basis, which means the company will use however much semen it takes to result in a pregnancy. The rates for this range from 1,400 to 6,500 Canadian dollars (I think subtract 7% for U.S. dollars). In my opinion, it would be great to have a guaranteed pregnancy but the cost would be having to bring a mare to one of their facilities and pay to have her boarded and all of the necessary procedures accomplished.

The second part of this company that I found very interesting, is whole they only sell frozen semen by means of a guaranteed pregnancy, they do not require that a stallion owner interested in frozen semen bring the stud to their facility. Though the prices are slightly high, the clinic will actually transport a dummy phantom. They say that the only thing the stallion owner needs to supply is a good place for the horse to have solid footing and the stallion. At the clinic I worked at, collections were done using a teaser mare, unless on a rare occasion, the stallion was better off without one. This site does not mention a teaser mare and I wonder how they train stallions that have never jumped a phantom.

Finally, it strikes me as odd compared to other services that this company runs much more like a business than a veterinary clinic that simply performs services as clients request them. This business makes embryos and stores them frozen. They then can, at any time sell them and transfer them. They say the pregnancy rates for these frozen embryos are 60-70%. I will have to look into the process of freezing an embryo, because I am not familiar with it. Equine Embryos also sells foals that are the result of embryo transfers, I wonder if they absorb the cost of the pregnancy in order to sell the foal, or if they are the result of contracts that never were fulfilled on the part of the client. They also seem to keep several high performance horses either on the farm or in close proximity because they advertise that someone can lease one of these donor mares and I would assume choose any stallion (within reason) to create an embryo with.

So, chew over this site a little, it gives a few ideas of what services are available for someone wanting to have a foal, as they say, from almost any combination of stallion and mare. I do believe that some of these services are not commonly offered by most clinics and it will be interesting to do more in depth comparison.

Some Details on ET

This is a photograph of what would happen most of the day at the clinic, the veterinarian is checking a mare most likely for ovulation or the progress of a follicle. We would do checks like this for pregnancy as well, usually at 7 days after a transfer then again at 14, 21 and 53. The checks are actually recorded as days from ovulation so they would eb 14, 21, 30, 60 and maybe 45.

I would like to discuss the content of two specific sites in this blog. The first is an article from the University of Idaho, Departments of Animal and Veterinary science. The article is written by D.K. Vanderwall and it goes over many of the specific procedures that constitute embryo transfer. The author gives 6 reasons that embryo transfer is useful in the business of broodmares, these I have found are pretty consistent between vet schools and practices. The reasons one would be interested in investing in an embryo transfer would be:
1. To obtain a foal from a mare that was currently performing at a high level
2. To get many foals from any mare (more than one a year)
3. Research purposes
4. Obtaining foals from mares that are two years of age (younger than one would usually breed)
5. Obtaining a foal from a mare that was not reproductively sound
6. Getting a foal from a mare that has other prohibitive health problems such as a tendency to founder

The article contains a brief history of the procedure, stating that the first successful pregnancy as the result of an embryo transfer occurred in 1972, though it was not until the 1980s that the procedure was considered common practice and held validity in the area of veterinary medicine. The next major development was the possibility of storing an embryo in cooled media for several hours. Of course this development allowed facilities to extract embryos and ship them to a location that housed a recipient mare. This makes it possible for the owner of the donor mare to have the procedure done without moving traveling long distances but most importantly they do not have to also keep a recip. mare available and synchronized with the donor.

The part of this article that interests me most is the data that the author sites for the success rates of many veterinarians. The first set of data compares the success rate for embryo recovery dependant on the day post-ovulation that the embryo was collected. The trend increases from 58% with a 6 day embryo all the way to 71% for a 9 day. The data for the 9 day embryos particularly catches my attention since the veterinarian I worked with did not collect any 6 or 9 day embryos. The reasoning for this, as I understand it, is that the likelihood of finding a 6 day is less (as the data shows), but I believe they did not try for 9 days because the embryo would be potentially too large to handle safely or with the most ease.

One final area of interest from this article is the surgical implantation of the embryo. I am not at all familiar with this method, which involves surgical sterilization of the flank followed by making an incision in the flank. Next, the uterine horn is located and a small puncture hole made, the embryo is then deposited into the horn and the uterus is simply pushed back into the mare without any suturing. It was thought (according to Vanderwall) that this method of implantation yielded higher pregnancy rates, though today the non-surgical method (the one I am intimately acquainted with) is just as, if not more successful.

I am planning next to discuss a commercial site which offers some interesting options of creating foals…

Embryo Transfer: how it works

In order to better understand the variations in the procedure, here is a brief description of embryo transfer in horses. The mare is inseminated and 7 to 8 days later, she is “flushed” by a veterinarian. In the method that I am familiar with, a bivona is inserted into the mare’s uterus. This is a long rubber tube that has one section that can be filled with air. This part is in the uterus and inflated to create a bubble that keeps the bivona in the uterus during the entire flush. Next, fluid that is special flush media containing some nutrients and antibiotics is run into the uterus one liter at a time. The fluid is then allowed to leave the uterus and flows into a small cup that had a very fine mesh filter at the base and the flush media flows through it, hopefully trapping an embryo. The whole idea behind flushing a mare is that the embryo is a loose body in the uterus and by filling the uterus to capacity many times the embryo bounces out of the uterus and ends up in the cup. It is believed that if there is any embryo in the mare, it will be out of the uterus after the first 2 liters. A very small amount of the fluid is kept in the cup and transferred to a Petri dish where it is examined by the veterinarian, under a microscope. The mare that has just been flushed will usually receive a shot of prostaglandin, depending on the value of the horse, we used lutalyse or estramate. The prostaglandin lyses any follicles forming or if there was an embryo that for some strange reason did not come out in the flush, it will abort the potential pregnancy. If there is an embryo found in the cup, it is washed with a special solution that does not harm the embryo and then it can either be shipped in cool solution or transferred to a recipient mare that has been synchronized and will carry the embryo. The transfer involves implanting the embryo via a catheter into the uterus of the recipient mare. The recipient mare then will get a caslicks which is the sewing together of labia so that air or bacteria will not get into the uterus and disrupt the pregnancy. She is also given 5-10 cc of progesterone and 10cc gentozen (an antibiotic) and the mares where I was were kept on Regumate to maintain progesterone levels until they were checked in foal at 60 days.

So this is a general understanding of embryo transfer, I will be researching other methods and talking in depth about the particulars and why certain drugs are used etc.

An Introduction

I was inspired to delve into the realm of equine reproduction after returning from an internship of sorts in Ocala, FL, as I mentioned previously. Though for the most part the blogging aspect of this information was prompted by a summer class I am taking, I think that my six moths in Florida warrants some reflection. You have to understand that I am not from a horse background. In the city, raised by a single mother who was neurotic about her housework, any pet larger than a small rodent was not tolerated. I went to Ocala in hopes of gaining some kind of education not only about reproduction but also a general confidence about being able to handle horses. The farm was mainly a clinic, though the client horses staying lengths of time for various procedures as well as the large heard of recipient mares made a majority of the chores related to any on a farm. So other than any veterinary work that was required to maintain the general health of the herd and the client horses (including colics, foal temps., diarrhea, lacerations, etc.), the majority of all work done was reproductive. The scope of services offered were not really restricted, we collected stallions to breed mares right away and we also shipped frozen semen that we collected overseas. There are a pretty large variety of breeding options for the mare owner and most of the services depended on the proximity of the mare and the semen or location of the stallion. Aside from the breeding component of the facility, the main source of business came from embryo transfers. The two sources of embryos were as a result of flushing a mare at the clinic or receiving an embryo that was shipped from another veterinarian. The veterinarians would rectally palpate the recipient herd (those that were actively in heat) daily or as needed to see if they had ovulated and armed with a list of client mares that had ovulated, they were responsible for making sure that there was a recipient mare for each client.


Throughout the course of the blog, as I explore the various options and views in equine embryo transfer (and probably other fields of reproduction) I will most likely be referring quite a bit to my personal experience. I am hoping that this will not cause an overbearing bias towards the methods of other clinics, but as I go through the information out there I hope that the comparing and contrasting will be useful. Again the previous bit is just let you know where I am coming from and to warn in essence that there will no doubt be much discussion related to my personal experience as I uncover novel bits of information.

Preliminary Post

During the next seven weeks or so, this Blog will be updated frequently and will focus on the subject of and concerning equine reproduction. There are a whole lot of directions that my research could go in but I think as of now I will focus on embryo transfer and the various steps it takes to successfully obtain an embryo (not an oocyte) from one mare and transfer it to another. Supposing this is the main vein of my blog, one article I may come back to is from the Feb2006 issue of "DVM: The Newsmagazine of Veterinary Medicine" and it is written by Ed Kane. The abstract says that the article reviews various agents that will cause a mare to come into estrus and some that will ovulate. The principle of induced ovulation as it is related to embryo transfer is that the donor mare and the recipient mare must have ovulated within a specific number of days so it may be necessary to cause one or both of the mares to ovulate.

Another article not directly related to embryo transfer but on the topic of hormonal regulation in pregnant mares is authored by J.C. Ousey and is in the August 2004 addition of Reproduction in domestic animals. The best bridge between embryo transfer and the entire cycle of hormonal regulation of a mare before and during parturition would be to look at specifically what could cause an acceptable donor mare to abort the fetus after a substantial period of time, and are these the same things that cause a normal mare carrying her own fetus to abort? A phenomenon that I saw twice during my stay at an equine reproduction facility in Ocala, FL was a blighted ovum, or an embryo that was alive when transplanted but for some reason never developed once in the recipient mare. I have not found any research on this yet, but it sounds like something fascinating to look into. One last study I found which also is intriguing studied what happened when both fresh and thawed frozen semen were injected via a drill cytoplasmicly into oocytes which were then developed in a lab as well as in a live horse (in vitro and in vivo, respectively). The study is published in “The Journal of the Society for Reproduction and Fertility” in 2002. It would be interesting, since this is four years old to see how the outcomes and observations compared to more recent successes in live embryo transfer today and if the practice of implanting semen in this manner is still an accepted and useful practice.