Is It Possible to Breed Less “Spooky” Horses?
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Wild horses possess an instinct to stay vigilant, constantly on guard against potential predators. This innate behaviour remains ingrained even in domesticated horses, causing them to be easily frightened and alert to potential dangers.
Horses often struggle to differentiate between genuine threats and harmless objects, such as a plastic bag floating past a riding arena. As a result, some horses may react to these perceived dangers by rearing, bolting, or bucking, creating hazardous situations for both themselves and their riders.
University of Florida researchers are working to identify genes that influence horses’ tendency to react to these “spooky” plastic bags. Identifying these genetic traits would be a first step towards one day selecting or breeding horses for the temperament types we prefer. These research results might be a decade away.
Samantha Brooks, associate professor of equine genetics at the University of Florida Institute of Food and Agricultural Sciences, along with her team, conducted an experiment on several groups of young horses from the UF/IFAS breeding program to gain insights into startle responses.
The horses wore wireless heart-rate monitors and were loose in a round pen. At set intervals, an umbrella was opened quickly within the animals’ line of sight. The team analysed the animals’ behaviour and change in heart rate throughout and after the initial startle reaction.
“We can’t read their minds,” said Brooks. “Their heart rate tells us what is going on inside that we cannot see from reading their body language alone. It was interesting to see the stories their heart rates told us.”
The team found that two clear groups of horses emerged from the data. The first group was startled by the umbrella opening, had a spike in heart rate, maintained a reactive or hyper-alert state including more time spent looking and moving away from the umbrella. The second group startled much like the first group to the umbrella opening, but with a different outcome. The horses experienced a spike in heart rate but then calmed quickly and carried on with their day. These animals perceived the stimulus and found it startling but did not to go through the behavioural patterns of avoidance and fear like the first group.
“Horses have adapted over thousands of years to live with people,” said Brooks. “Some of those changes include a reduction in startle response and are really helpful to better understand the horses we work with today.”
Now that two clear groups have emerged, the team will take this information and develop a study to differentiate the genetic components that make up how horses react to fear. Blood and hair samples were taken from each horse in the study for future analysis.
They plan to conduct a genome-wide association study (GWAS) in which the genome of the horses is scanned to identify genetic variations that differ between the two groups, By analysing a large number of genetic variants across the genome, they hope to identify regions or specific genetic markers that are associated with behavioural startle reactions.
Knowing how genetics influence behaviour can help horses and owners find their right fit.
“Understanding each horse’s genetic makeup will help you understand the type of animal you need,” said Brooks. “If we learn early on what this animal’s natural tendencies are most likely to be, we can make educated decisions on training and future careers to give the horse the best shot to grow into their potential, rather than becoming a problem or danger.”
Additionally, understanding a horse’s reaction to uncomfortable situations can make a difference in how they are handled for medical procedures, transportation and more.
“It’s important to know these traits because it can impact how we care for horses overall,” said Barclay Powell, a Ph.D. student working on the project. “This will be hugely important to the veterinary field as well. It’s not only helpful for the people handling the animals, but also for the horses’ welfare.”
“It doesn’t matter if the horse is a racehorse, therapy animal or driving a carriage, an unplanned startle response is generally a problem,” said Brooks. “We are just beginning to scratch the surface of this. It might take us 10 years or more to really have a clear understanding, but it is worth the effort.”
Funded by the National Institute of Food and Agriculture, this project was a collaboration between scientists and students studying equine genetics, behaviour and welfare science.
For more details, see:
Behavioral and Physiological Reactions to a Sudden Novel Object in the Weanling Horse: Quantitative Phenotypes for Future GWAS
Barclay B. Powell, Kelsey C. Horvath, Tyeler L. Gilliam, Kimberly T. Sibille, Andreas Keil, Emily K. Miller-Cushon, Carissa L. Wickens and Samantha A. Brooks
Genes 2023, 14(3), 593;
