Long-time Equine Reproduction Laboratory (ERL) team members Dr. Jennifer Hatzel and JoAnne Stokes are the magicians who help clients achieve their foaling goals through our assisted reproductive technology program.

What is your role at the ERL?

Hatzel: I’m an associate professor in equine reproduction, so I am involved in clinical service, teaching, and research. I specialize in clinical assisted reproductive technology for horses. JoAnne and I run the clinical assisted reproductive technology program here that helps horse owners achieve pregnancies from their mares or stallions using advanced techniques when traditional methods have failed. This includes artificial insemination, embryo transfer, OPU/ICSI (oocyte pickup/intracytoplasmic sperm injection), and other specialized procedures.

Stokes: I work as a research associate. I primarily handle the lab work, preparing everything for the aspirations and performing sperm injections. I also vitrify embryos and prepare ICSI-produced embryos for transfer, fresh and vitrified. Additionally, I’m responsible for quality control in the lab, maintaining the incubators, making media, and other related tasks.

What do you want people to know about the assisted reproductive technology program?

Hatzel: Our program has a rich history. We’re very fortunate because we get to stand on the shoulders of some giants who laid the foundation for techniques the entire world is using nowadays.

The work started in the late 90s and early 2000s, moving from the bench top to the barn. It was modeled after techniques developed for human couples who suffer from fertility issues and are seeking assistance. Also, in the cattle industry, it is used to breed next generations for higher milk yield in dairy cattle or improved quality for beef cattle.

Equine researchers saw these advancements and said, “hey, I wonder if we could make this work in the horse.” Following years of research, becoming more efficient, and achieving better results, we transitioned to offering assisted reproductive technologies as a service. We have continued to find ways to tweak different things to reduce costs and increase success rates.

After working to help problem mares achieve pregnancy, there was a shift to focus on the stallion. For example, helping achieve successful pregnancies after a valuable stallion dies and only has x number of frozen semen straws. So, it’s not just problem mares we’re working with; we also see younger mares who may have never had a foal before, and this was their first attempt at trying something to achieve a pregnancy to extend a stallion’s line.

Stokes: We can receive ovaries from mares that have died. Once the oocytes are collected, we can do ICSI and hopefully produce an embryo that becomes a foal.

What does a typical day look like?

Hatzel: It’s a heavily seasonal job. Horses only reproduce in the spring and summer; more or less, their physiology is intended to reproduce when the day is the longest. So, for us, anywhere from February through August is considered our breeding season. It’s a concentrated time during which people try to achieve their goals of getting their mares pregnant through various mechanisms.

The day can start with just checking mares that are here in-house to see when they will be ready for a procedure to collect their oocytes, transfer embryos, or artificially inseminate. Then, we learn that a mare just gave birth, so we have to run over and check the baby. Next, we might need to order semen from somewhere across the country and move on to flushing embryos out of a mare, performing embryo transfers into recipient mares, and managing those recipient mares.

So, we’re all running around like chickens with our heads cut off for several months.

Stokes: The mornings consist of checking the incubators to make sure they are working properly. Lab quality control is of the utmost importance. Media will need to be prepared, and the lab and stocks will be set up for aspirations. Next on the list is performing sperm injections and checking the progress of developing embryos in the incubators. Somewhere in the middle, we transfer or vitrify ICSI-produced embryos.

What is the most meaningful part of your job?

Hatzel: We have a lot of clients in Wyoming, Nebraska, all the way to Utah, and the Dakotas, so it’s not as convenient for them to trailer back here for foaling, but some do deliver with us. We see more of our local clients bring their mares back, so if we get to be a part of that, that’s a really big cherry on the top of our work. But even getting to see that healthy, happy foal on the ground on social media is very rewarding. To be a part of, “I knew this foal when it was just a single cell and now it’s a baby on the ground” – that’s pretty awesome.

Stokes: I agree with Dr. Hatzel; seeing happy and healthy babies makes the hard work rewarding.