Embryo Transfer & Cloning

In my previous post, I discussed various horses I had owned or ridden in my youth. Several of my past horses were acquired in unusual ways. Additionally, my love of Arabians was a direct result of my sister’s love of the breed, as I inherited the horses she initially rode. When I was a child visiting my cousin’s farm in Illinois, I didn’t know about the Babson Arabian horse farm a mere 20 miles away. I first visited when I was in my early twenties and in veterinary school.

Homer Watson

Homer Watson was the farm manager for Henry Babson and Homer clearly had significant impact on the breeding and development of the Babson line. He was still alive when I first visited the farm. Homer was training his replacement, John Vogel, at that time. The place was amazing, with eat-off-the-floor cleanliness. They were expecting at least a dozen foals that year (around 1980). I very clearly remember John having some perception that the phase of the moon during breeding had something to do with the gender split of the foal crop! I remember researching it and finding little scientific proof, but it was still fascinating.

When Homer learned I was in veterinary school at Purdue, he made a proposal. He had a very well bred, expensive mare that he couldn’t get in foal. As per their usual farm protocol, she wasn’t bred until she was three, to foal at four with nothing but the best veterinary care. Unfortunately, nature doesn’t always get it right. The foal was upside down and a foot went through the top of the uterus into the colon. The resulting infection left the mare unable to maintain a pregnancy after that. Her name was Saanda and Homer wondered if perhaps we could accomplish embryo transfer at the veterinary school? IF we could get her in foal, we would share the value of that foal…. such a deal!

Impossible challenges

Saanda came home with me, but there were logistical aspects to this arrangement that made it very complicated. We had to synchronize her with a potential recipient mare. Embryo transfer in cattle was in full swing at that point. Cattle are much easier though, as they can be “super-ovulated” (meaning up to 30 eggs can be flushed at a time!) Not only that, but the eggs of a cow can be flushed and seen under a microscope even if they aren’t fertilized and turned into embryos.

In horses, super-ovulation (at least in 1980) was not possible. If the egg wasn’t fertilized it never made it into the uterus. Therefore, it was impossible to tell if Saanda’s uterine scarring extended into her Fallopian tubes rendering her unable to even flush out accessible eggs. If we flushed and found nothing, did that mean no egg was available for fertilization, or an egg was present but fertilization didn’t occur?

The other huge issue with this was that the other half of the pregnancy equation… the stud… still resided at the Babson farm in Illinois! The farm was about 300 miles from Purdue. So after the mares were synchronized, Saanda had to be transported to the farm for breeding, left for a few days, and then retrieved and hauled back home.

Serr Kari

Eventually, Homer donated a young stud to Purdue. His name was Serr Kari and I talked about him in this previous post. The hope was that on-site breeding would at least eliminate the stress of hauling all the time. The trouble was, Kari’s fertility was not ideal. Line breeding can have undesirable consequences.

We tried multiple cycles of synchronizing the mares. The process starts with flushing the uterus to retrieve an embryo, and hopefully planting that embryo into a ready-and-waiting recipient mare. We were never able to even retrieve an embryo. We didn’t know if that was because no egg could make it to the uterus, the sperm was inadequate, or we just never got lucky with fertilization. Eventually, we finally gave up.

Saanda continued to live with me unofficially. I broke her to ride at the ripe old age of 17. My kids would ride her bareback around the pasture. She was so uncollected and strung out I used to say that she covered the entire length of the pasture when they rode her, but she never gave them a hint of trouble. She colicked at 24 and I can still remember standing in the dry lot in tears, on the phone with John Vogel and asking him what he wanted me to do. No matter how heavily we drugged her, we could not alleviate her pain. I had to put her down.

A few years later, Purdue called and asked me if I wanted Kari? Of course I did… so they gelded him and he came to live with me at age 7. He was not always the best dispositioned horse (although he never tried anything with me) but he was a great ride. I lost him to Cushing’s Disease before he was even 20.

Equine reproduction today

Equine embryo transfer has come a very long way in nearly 30 years. A few years ago I participated in a Brent Graaf Horsemanship clinic. During my week on Brent’s farm in Texas, we visited a facility not far away that was quite progressive in equine reproductive technology. I was amazed at the advancements that had been made. I heard the story of a famous bucking horse mare that had been cloned. Her clone, as a young foal, immediately gravitated to the older mares who had actually bonded to the original, cloned mare. There were many horses housed in a large area. There were both originals and clones, and the foal had many options for companionship. However, she chose her “old friends”! If I remember correctly, it cost about $150,000 to produce a clone at that time.

On an entirely different note, I have blogged many times in the past about my beloved dog Reilly. I was devastated when I lost her last summer. I am happy to report that very soon a new Border collie pup will be joining my household! “Kara” will be 8 weeks old on March 29th. I am so excited! Stay tuned for more details to come!