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In 2025, the second edition of the Audevard Trophy – In Equine Vets We Trust took place.
Discover the interview with Axelle Marie, junior veterinarian at the Méheudin Equine Veterinary Clinic and overall winner of the Trophy for her thesis entitled:
“Comparative evaluation of the embryonic and fetal mortality rate after transfer in receiving mares from fresh in vivo produced embryos and frozen in vitro produced embryos after intracytoplasmic sperm injection (ICSI) of oocytes matured in vitro during four breeding seasons (2021–2024)".
Through this initiative, our aim was to support future equine veterinarians at the start of their careers and to promote the sharing of scientific knowledge within the industry.
1. Could you tell us about your thesis and what motivated you to choose this particular topic?
My thesis is a comparative study of embryonic and fetal mortality rates following embryo transfer in mares, conducted at the Haras de Hus over four breeding seasons, from 2021 to 2024. It compares the survival of embryos produced in vivo (“fresh embryos”) with that of embryos produced in vitro using the OPU-ICSI technique and subsequently frozen, with fertilisation performed at the Avantea laboratory in Italy.
The study analyses 1,339 embryo transfers drawn from an initial database of 1,639 transfers, representing a large, homogeneous and representative cohort within a high-level breeding programme, primarily focused on sport mares.
My interest in this topic emerged early on. From my first year at the Nantes Veterinary School, I worked weekends as a veterinary assistant at Hus Reproduction, where I discovered equine reproduction. I was fortunate to observe numerous assisted reproduction procedures, ranging from insemination and embryo transfer to oocyte aspiration. Over these five years, I had the opportunity to engage in in-depth discussions with Hus clients, who have shown increasing interest in new assisted reproduction techniques such as OPU-ICSI. This led me to question many aspects of these techniques myself, and I began an extensive review of the scientific literature, eventually realising that several key points remain debated. This is particularly true for the comparison between the survival of in vivo embryos and ICSI embryos, a central concern for sport mare owners, which ultimately prompted me to propose this topic to Professor Jean-François Bruyas at the veterinary school.
2. Do you have an anecdote to share about this work? A memorable moment? A challenge you faced?
Looking back, what stands out to me about this thesis is that it was ambitious and demanding, particularly in terms of statistical analysis, with a database of over 1,300 transfers and very complex survival analyses. However, it proved to be extremely formative. I developed a genuine interest in equine reproduction, and this thesis taught me how to search the scientific literature efficiently and critically, a skill that is invaluable in my daily work today.
Moreover, obtaining such robust results and being able to compare them with published data was extremely stimulating. In my view, this is one of the most striking aspects of the project.
3. How do you think your work can contribute to the advancement of equine veterinary medicine?
This study helped to better characterise the survival dynamics of embryos produced by ICSI compared with those produced in vivo. It shows that the increased fragility of in vitro embryos is mainly expressed during the early embryonic period, before 14 days of gestation. Once this critical stage has passed, their survival rates become comparable to those of in vivo embryos.
These results have already had a practical impact at the Haras de Hus from the 2025 season onwards, notably through reinforced systematic monitoring at day 14 post-transfer and adjustments in the management of recipient mares to optimise success rates, particularly for summer transfers or when reusing recipient mares. The study also highlighted the influence of several factors, such as the number of embryos collected during a single in vivo cycle, embryonic sexing by biopsy of in vitro embryos, reuse of recipient mares within the same season, and seasonal effects, with a higher risk of early embryonic loss when transfer occurs in summer.
I believe this thesis can therefore help provide more objective answers to breeders’ and owners’ questions regarding reproductive strategies, and allow reproductive monitoring to be more finely tailored to the sporting context of mares, improving case-by-case decision-making.
Beyond the answers it provides, this work also opens the door to further research, including the study of additional factors such as weather conditions or the duration of frozen embryo storage, which are already being investigated in the same study population.
4. Is there an inspiring figure who has particularly influenced your career path?
Without hesitation, I would cite Dr Hubert Terris (and the entire Hus Reproduction team). He gave me the opportunity to discover high-level equine reproduction and to take my first steps in this field. Beyond technical skills, he instilled in me a strong sense of rigour and true perseverance in my work. To me, he embodies this constant drive to do better, to continue learning, and never to be satisfied with what has already been achieved.
During my clinical rotation at the Nantes Veterinary School, he also allowed me to witness the birth of the foal of one of the first mares I had inseminated a year earlier. It was at that moment that I fully grasped the meaning and beauty of the work carried out over those five years.
5. What are your professional aspirations following this award? How do you see your future as an equine veterinarian?
I am currently working as a junior veterinarian at the Méheudin Equine Veterinary Clinic, alongside specialists from whom I learn a great deal on a daily basis. Equine reproduction is undoubtedly the field that attracts me the most, but above all I enjoy equine medicine as a whole. In the longer term, I therefore aspire to become a general equine ambulatory practitioner, with a strong commitment to high-quality practice grounded in current scientific evidence.
Looking further ahead, I also plan to obtain the certification as a breeding centre manager as soon as possible and, together with Professor Jean-François Bruyas and Dr Hubert Terris, to present the results of this thesis at various conferences, including internationally, in order to continue exchanging ideas and learning alongside other professionals in equine reproduction.
