A New Era of Thoroughbred Breeding

A New Era of Thoroughbred Breeding

Breakthroughs in genomic technology have revolutionized the field of equine genetics, making it possible for thoroughbred owners to unlock the secrets hidden within each horses genetic code.

These game-changing findings provide a blueprint for informed decisions about training, management and breeding that can lead to better performance and overall welfare for thoroughbreds in the racing industry.

benefts of genetic testing thoroughbreds

Nature versus Nurture

Several traits can enhance racing performance in thoroughbreds, including the capability of a horse’s muscles to take in oxygen, the density and construction of the bones, and the ability to process education and training.  But by looking a gangly yearling, it is not easy to understand whether that horse will develop into a champion, or a racing dud.

Many horses never get close to showing what they are capable of because of physical or emotional genetic influences. that could, with the right knowledge, be used positively to give them an edge. For example, if a later maturing thoroughbred with staying lines is pushed into training too early and entered in two year old races – it could suffer a career ending injury. If that horse instead was given more time, and trained for endurance on hills instead of sprints on synthetic tracks, it might have been a derby winner. Equally so a horse with high reactivity could benefit from living in a more natural environment (turned out in a paddock rather than kept in a stall) to ensure less anxiety while racing.

This is because a horse needs to be mentally, as well as physically, strong to handle a life often confined for many hours, unable to socialize with other horses.

Genetic testing can help owners discover traits that influence their horses ability to cope with artificial living situations (like stabling and isolation) and base management and nutritional decisions on these factors.

Famously reactive thoroughbreds

Famous examples of racehorses with nervous or unpredictable personalities include six-time Group One winner ‘Gold Ship,’once rated the eleventh-best racehorse in the world.

Gold Ship was well known for his unpredictable and often dangerous temperament, and along with major wins, had disastrous performances. Jockey Norihiru Yokoyama said of the horse, “He’s a clever horse, and whether he performs well or not just depends on his mood.”   

The aptly named ‘Mad Moose’ was another example. The chestnut gelding won more than £100,000 in prize money before the British Racing Authorities banned him for ‘refusing to race’.

Australian mare Chautauqua had a series of 6 sensational group one wins that earned her the nickname ‘the thunder down under’ one day refused to leave the start gates, much to the dismay of her owners and trainer.  It wasn’t a one off either. The stress of racing was too much for her.

Mad Moose and Chautauqua were retired from racing and successfully retrained as dressage horses, They thrived in homes that provided them with an alternative ‘stress-free’ lifestyle. If, while racing, these horses had been offered the same lifestyle – would they have enjoyed longer, less explosive racing careers? Probably so.

Highly vigilant horses usually fail to succeed in high-stress environments (like racing stables) but they can live long and happy lives when provided with a more natural management system, plenty of turnout and forage and a set training regime.     

Curious horses are better suited to a racing stable lifestyle

Curiosity and low vigilance are advantageous traits for racing as they can influence early mental and psychological responses to training.

It is easier for horses with genetic variants indicative of a calm and curious disposition to accept unnatural (at least to a horse) practices such as confinement, isolation (stabling or transportation), and intensive training. These favorable temperamental traits may result in a longer racing career than horses with high reactivity and fear based dispositions.

Balancing Performance and Long-Term Health

Understanding which horse are genetically at risk of injury (and when) can help guide training and management decisions and improve future generations of racehorses.   

Bone injuries are often misdiagnosed in racehorse, and the serious complications usually develop because horses with unrecognized injuries are raced or pushed to race over distances they are not genetically able to run. Thus causes them to succumb to the effects of fatigue (which can cause them to lose their balance and fall, or suffer heart and lung distress).

A study of two- and three-year-old racehorses euthanized due to catastrophic fractures during racing found that 77% of them had evidence of pre-existing stress fractures at necropsy.  

Another study by Animal Aid of 11 equine fatalities at the four-day 2006 Cheltenham Festival shows that every one of the horses that died had sprint racing bloodlines (not made to run a race of this length). The same was true of the two horses that died at the 2006 three-day Aintree steeplechase meeting.  

A 2008 paper showed that more racehorses made it to the starting gate in 1968 than in 2008. Even with all the advances in science made over the past half-century, fewer racehorses today make the grade, and those that do, retire prematurely more frequently than horses forty years ago. This may be because we are trying to race horses over distances they are not bred to run.

Just like human runners, some thoroughbreds are born with muscles that are better suited to sprinting, while others have muscle fibers suited to long-distance sports.  

Understanding whether a horse will develop powerful muscles built for explosive bursts of speed or muscles that are built for lasting endurance gives owners the ability to choose an athletic discipline suited to each horse’s unique genetic blueprint.

Can genetic testing be used as an evaluation tool for welfare associations?

Genetic testing of the Myostatin gene mutation can be used as a predictive evaluation tool for equine welfare associations.

Thoroughbred welfare associations can use the power of genome testing to deliver a better quality of life for retired racehorses transitioning into equestrian sports.

By unlocking a horse’s genetic code, intermediaries can identify physical characteristics and traits to help them with retraining. This leads to increased safety during retraining, and later when the horse is repurposed and adopted out- therefore reducing the risk of injury or mistreatment.

Knowing exactly what each thoroughbred needs on an individual basis is key when it comes to supporting their success throughout their second career.

For example: horses with the MSTN mutation are genetically suited to sprint races and intense sports like barrel racing, relays and polo. These horses mature early and often have a bulkier muscle composition than other horses – the muscle structure and function is ideal for explosive speed over short distances but less suitable for endurance sports.

Thoroughbreds with a high proportion of slow-twitch muscle fibers have a better chance of success in longer races (and later sports like eventing or endurance) since they are genetically suited to perform best in an activity that calls for long-duration, low-intensity exercise. These horses are more resistant over long distances than sprinter types, but their limbs are longer, and their structure is slow maturing – and sometimes they don’t come into their own until they are five or six years old.

Tap into the power of individual genetic expression

Now that full genome sequencing technology is accessible to thoroughbred owners, this exciting technology can be used to enhance any horses developmental and athletic capability and (when used in conjunction with good nutrition and training) ensure better performance during racing and a longer and happier life afterwards.  

Learn more about our Thoroughbred genetic tests

Have a question for us?