How this agri scientist is investigating on-farm fertility

UL’s Prof Sean Fair discusses his research on bull fertility, the ‘life blood’ of an academic and how he’s using AI and machine learning.

Today (17 September) marks the final day of the National Ploughing Championships 2026, Ireland’s largest outdoor agricultural event.

The spotlight has been firmly fixed on all-things-agriculture at the event in Co Offaly this week, including the ways that science and technology are being used to advance the sector.

For example, earlier this week a number of agritech start-ups showcased their ideas at Enterprise Ireland’s Innovation Arena live pitching competition at the Ploughing Championships, with Roscommon’s VetPal taking home the top prize – the €10,000 Start-Up of the Year award.

Science and tech are more important than ever to Irish agriculture, with a number of researchers and founders alike focused on innovating and transforming various aspects of the country’s largest indigenous sector.

Prof Sean Fair is one such researcher.

Growing up on a livestock farm in Galway, Fair got a “deep hands-on start” with animals very early on.

“Caring for newborns and watching them thrive has always felt special,” he tells SiliconRepublic.com. “I never set out to become a researcher – I simply followed the questions that fascinated me and wanted to understand things more deeply.”

This curiosity eventually led Fair to a PhD in reproductive biology, where he was able to work alongside inspiring people across both research and the agriculture industry.

Now, Fair is head of the Department of Biological Sciences at University of Limerick (UL) and coordinator of the BullNet project – a Marie Curie Doctoral Training Network focused on understanding and improving bull fertility.

“I really enjoy having the academic freedom to follow my interests, and being able to progress assisted reproductive technologies in livestock allows me to be able to give back to the type of farm I grew up on,” he says.

Here, Fair talks to us about his research and the BullNet project.

Can you tell us about BullNet and the research you’re currently working on?

Global demand for meat protein is rising steadily, driven by a growing world population and a consumer preference for natural, nutrient-dense foods. Animal production systems urgently need to adopt technological efficiencies and more sustainable practices to reduce environmental pressures.

Farmers can selectively breed more genetically elite animals that grow faster, use feed more efficiently and produce fewer emissions per kilogram of meat, thereby reducing their hoofprint on the environment. Assisted reproductive technologies such as artificial insemination, sex-sorted semen and embryo technologies allow us to disseminate genes from elite animals more widely so as to enhance genetic gain for economically and socially important traits.

BullNet is a Marie Skłodowska-Curie Actions Doctoral Training Network that I coordinate, and we have 14 PhD students based across Europe working on various aspects of bull fertility.

It is focused on understanding and improving bull fertility, and comprises of a multidisciplinary and inter-sectoral research programme designed to unravel the complex underlying biology of compromised fertility of individual bulls.

We use cutting-edge basic, applied and machine-learning approaches to understand the biological regulation of sperm function and testis biology. One of the main themes of my own research is why some bulls have sperm that has normal motility and shape, as assessed under a microscope, but result in reduced pregnancy rates in the field.

We are also studying how sperm cross-communicate with both the male and female reproductive tracts, how this affects the establishment of pregnancy and how paternal epigenetic contributions are passed on to the next generation.

How is AI and machine learning transforming your research area?

We are using AI and machine learning in a systems biology approach by integrating large omics-based biological datasets (genes, proteins, metabolites) to more comprehensively understand the underlying biology of the male contribution to pregnancy establishment.

For example, we have recently shown that while only one sperm fertilises the egg, the millions of other sperm interact with the lining of the uterus and fallopian tubes and alter its environment for the benefit of the developing embryo. So it’s a team effort!

We now know that sperm need to be alive to stimulate an immune response in the uterus – and indeed, sperm from different males do this differently. Sperm from high-fertility bulls upregulate biological pathways related to embryo development and promote the establishment of pregnancy. We have also used machine learning tools to identify proteins on the sperm surface which we have validated as more reliable biomarkers of bull fertility.

In short, it brings forward biomarkers and biological pathways that we would never have thought of and allows us then to follow new avenues of research. This has implications for other species, including humans.

How can this research transform farming practices?

Being able to reliably predict the fertility outcome from a semen sample prior to its release into the field is crucial, especially for young, genetically elite bulls in their first season. Because of DNA technology, we can now identify the most elite bulls within weeks of birth. But these young bulls don’t produce functional sperm until they reach puberty at approximately nine months of age, and even then, they produce low volumes of poorer quality semen – and we don’t know their pregnancy rates in the field.

By having reliable biomarkers of semen quality, the animal breeding centres can release semen from these young bulls (both sex-sorted and conventional semen) with confidence that farmers will achieve normal pregnancy rates. On-farm fertility is a key driver of profitability on grass-based livestock farms.

‘Funding is the life blood of an academic’

What are some of the biggest challenges you face as a researcher in your field?

Constantly seeking out funding opportunities to sustain my research. Funding is the life blood of an academic and in the university sector we don’t have a core research budget. The Irish and EU funding scene is very competitive and while I am lucky to have secured a number of large-funded research projects, it is always a challenge to ensure there are not gaps in funding as we would lose staff that have built up high levels of expertise.

Are there any common misconceptions about this area of research? How would you address them?

That we are editing the genome of animals. Our focus is to work with the wider animal breeding industry and geneticists who identify the most elite animals for traits of interest and then we use assisted reproductive technologies to widely disseminate the genes from these animals.

So it’s perfectly natural and while we work with bull sperm, in reality this is only a means of disseminating DNA from the paternal line.

Is there other research in your area that you’d like to see tackled in the years ahead?

In vitro gametogenesis is a laboratory technique that turns somatic cells, such as skin or fibroblasts, into functional eggs or sperm by first reprogramming them into induced pluripotent stem cells and then guiding them through germline development.

This has been accomplished in mice, and I would like to see this being developed in livestock as it has the potential to rapidly speed up genetic progress when combined with other assisted reproductive technologies. As these technologies evolve, it is essential that we conduct well-designed experiments to monitor any off-target effects in the next generation.

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