UC Davis Veterinary Assisted Reproduction Laboratory

09/03/2026

Another paper from our lab looking at how we can improve equine OPU-ICSI outcomes! 🐴

More and more evidence suggests that better OPU results may come from targeting the right time in the follicular wave. But how do we identify that time?

Our new study shows that follicle size alone may not tell the whole story. Follicles of the same size can have very different hormonal environments, reflecting different physiological stages and developmental trajectories.

The next step is moving beyond simply asking “How big is the follicle?” and better understanding where that follicle is in its life cycle.

08/30/2026

🐴 CENTRAL VALLEY BREEDERS, WANT TO LEARN ABOUT THE NEWEST ADVANCES IN EQUINE BREEDING? 🧬✨

Have a valuable mare you didn’t get settled this year?
Interested in producing foals from a mare without carrying the pregnancy herself?
Curious about OPU, ICSI, and Embryo Transfer and whether these technologies could be right for your breeding program?

Valley Veterinary Services has your solution!

We’re excited to partner with UC Davis for a FREE Equine Reproduction Seminar designed specifically for horse owners and breeders!

Join Dr. Kayla S. McCrone and the UC Davis embryology and advanced equine reproduction team as we discuss:

🐴 OPU (O**m Pick-Up) — collecting oocytes directly from your mare
🧬 ICSI — using advanced laboratory techniques to create embryos
🐎 Embryo Transfer — utilizing recipient mares to carry your valuable pregnancies
💡 How these technologies can open new opportunities for mares that didn’t settle this breeding season, performance mares, older mares, and valuable genetics

Come learn how these advanced reproductive technologies work, what to expect, and how they may fit into your breeding program!

🍽️ Dinner & refreshments provided
🎁 Giveaways
💰 Exclusive attendee coupons and discounts worth nearly $1,000 to help horse owners give these advanced breeding options a try!

❗ SEATING IS LIMITED! ❗

If you’re planning to attend, PLEASE RSVP using the QR code on the flyer so we can reserve your seat and plan accordingly.

We’re looking forward to an educational and fun evening talking about the future of equine reproduction! 🐴🧬❤️

Valley Veterinary Services × UC Davis
Bringing advanced equine reproduction within reach for horse owners and breeders.

Registration Link:

https://docs.google.com/forms/d/e/1FAIpQLScb-KuzbRUG2ReykqRXVLIuejNjw8AUUvRtavGLCbzcoUOJAg/viewform

08/30/2026

Check this paper out showing that perspectives on OPU–ICSI differ primarily according to familiarity with the procedure. Veterinarians and breeders who are not currently using OPU–ICSI are more likely to express concerns about it. Congratulations to all the authors!

08/24/2026

We had a great time at ISEET in Lexington! It was a wonderful opportunity to share our research, learn about exciting work from others, and catch up with colleagues and friends.

08/03/2026

It is finally out!

In this new study, we found that the horse fetus naturally undergoes a change in cholesterol-related metabolism that looks surprisingly similar to what occurs in Smith-Lemli-Opitz syndrome (SLOS) in people. This makes the horse a potential model to better understand the disease and may help guide future research and treatment development. Congratulations to Kate and all the co-authors. Very proud of this work and grateful to everyone who contributed.

DOI: 10.1210/endocr/bqag083

07/31/2026

Today we say goodbye to our outstanding resident, Dr. Thadeu de Castro, on his final day with the UC Davis Equine Reproduction Service.

We are also proud to celebrate his recent achievement of becoming a Diplomate of the American College of Theriogenologists (ACT), earning board certification as a specialist in animal reproduction.

Congratulations, Thadeu! We are proud of you and wish you all the best in this next chapter. 🎉🐴

Only in a theriogenology group could a cake with an “oocyte” and “sperm” be the highlight of the farewell party. Thanks, Dr. Babiche Heil, for the perfect send-off!

07/23/2026

Congratulations to Dr. Thadeu de Castro Thadeu De Castro on passing the board exam and becoming a Diplomat of the American College of Theriogenologists!

07/22/2026

07/17/2026

How are modern breeding technologies shaping the future of our horses? 🧬🐴

A new UC Davis Veterinary Genetics Laboratory ( ) study found a 1.38% decline in genetic diversity in American Quarter Horses ( ) over a single generation. Foals produced through assisted reproductive technologies (ART) also showed lower genetic diversity than those produced by live cover, largely reflecting the mares selected for these breeding programs.

The key takeaway is not that ART is the problem. ARTs are powerful tools that have transformed equine reproduction. Their impact on genetic diversity depends on how they are incorporated into breeding programs and breeding management. Thoughtful breeding decisions remain essential to preserve genetic diversity while continuing to make genetic progress.

Proud to be part of this great work.

07/08/2026

One of the most rewarding parts of academia, and especially UC Davis, is the opportunity to work with great people across disciplines.

This collaborative study describes the clinical, imaging, and histologic features of testicular seminoma in horses. Although this tumor is considered uncommon, the findings show that it can have important metastatic potential and may be associated with poor long-term prognosis.

Congratulations to all the co-authors!