Gut bacteria crucial to racehorses’ success

Gut bacteria found within Thoroughbred racehorses study reveals it's crucial to a horses success

Gut bacteria found within Thoroughbred racehorses at one-month-old can predict their future athletic performance, according to a new study from the University of Surrey. The study also showed that foals with lower bacterial diversity at 28-days-old had a significantly increased risk of respiratory disease later in life.

Researchers from the university’s School of Veterinary Medicine and School of Bioscience, led by Professor Chris Proudman, investigated the composition of gut bacteria in Thoroughbred foals bred for flat racing and its impact on their long-term health and athletic performance.

The study consisted of 438 faecal samples from 52 foals going under analysis, with respiratory, gastrointestinal, orthopaedic and soft-tissue health issues tracked from birth to age three. Alongside this, the team analysed information regarding finishing position, official rating, and total prize money earnings as measures of athletic performance.

Professor Chris Proudman, Professor of Veterinary Clinical Science at the School of Veterinary Medicine at the University of Surrey, said: “Minimising the risk of disease and injury is important for the welfare of racehorses, and maximising their athletic potential is important for their owners. We have found that gut health, in particular the health of gut bacterial communities very early in life, exerts a profound and enduring impact on racehorse health and performance.”

Researchers found that the athletic performance of the foals was heightened by higher faecal bacterial diversity at one-month-old. They identified that a higher number of the bacteria Anaeroplasmataceae was associated with a higher official rating, and increased levels of Bacillaceae at 28-days-old were linked to higher race placings.

The team also investigated the long-term impact of foals receiving antibiotics during the first month of life. It was found that these foals had significantly lower faecal bacterial diversity at 28 days old compared to other foals who did not receive such treatments. Further analysis revealed that these foals won significantly lower prize money earnings (an indicator of athletic performance) in their subsequent racing careers. In addition, foals who received antibiotics during their first 28 days of life had a significantly increased rate of developing a respiratory disease compared to their counterparts.

Foals who received antibiotics during their first 28 days of life had a significantly increased rate of developing a respiratory disease compared to their counterparts.



Professor Roberto La Ragione, co-investigator from the School of Bioscience at the University of Surrey, said: “Antibiotics are vital in treating infections and protecting the long-term health of foals; they do, however, need to be used responsibly. Our study demonstrates that treatment with antibiotics can disrupt the healthy gut microbiome with long-term impacts on health and performance. The next part of our study will examine how we can minimise disruption of gut bacteria when antibiotics have to be used to treat infections.”

Researchers also identified that low gut bacterial diversity in early life is associated with an increased risk of soft-tissue and orthopaedic issues developing later in life.

Dr Kirsten Rausing, Chairman of the International Thoroughbred Breeders Federation and, through her ALBORADA Trust, study sponsor, commented: ”This ground-breaking study has identified the importance of gut health in our very young foals. As breeders, if we can get this right, we will produce foals that will be healthier, and that will grow into more successful racehorses.”

Work is currently underway to develop novel probiotics that will enhance the gut health of foals in early life and to investigate how antibiotics can be used whilst preserving gut health.”

Katie Gilmour is the host of Poles, Piaffe & Prosecco: the podcast for riders that love to train, laugh and drink prosecco! The podcast is free to listen to on Spotify and Apple Podcasts

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