The hot-blooded nature of Thoroughbreds was revealed in a study exploring the behavioral and cardiac responses of mature horses to a novel object.
Researchers Kyung Eun Lee, Joon Gyu Kim, Hang Lee and Byung Sun Kim set out in a South Korean study to investigate whether breed, sex, and age affected temperament differently during a test involving an unfamiliar object.
The study included 12 Jeju-Thoroughbred horses (a popular cross in Korea), 15 Thoroughbreds, and 12 Warmbloods. The horses were typically aged 10 to 12, and 22 of them were mares.
The Jeju horse is a native Korean pony.
The horses were part of the horseback riding program at Cheju Halla University on Jeju island in Korea, and were not ridden more than once a day.
The researchers described an experiment that took place in an indoor arena involving a white plastic bag attached to the end of a one-metre stick.
Each horse was fitted with equipment to monitor multiple heart-rate variables. They were held by the same familiar trainer on a 5m lead rope. Once each horse was settled after a few minutes, baseline measurements were noted.
The trainer then gently revealed the bag-on-a-stick from behind their back and began using it to touch each horse’s left shoulder and neck.
The horses were scored on the basis of their behavior toward the novel object — in effect, the degree of their evasive response.
The test ended when the evasion responses ceased and their heart rate was back at baseline.
The results showed that the Thoroughbreds had significantly higher behavioral scores and readings in one of the heart-rate measures suggesting greater excitement and fear to the novel object in this breed.
None of the behavioral or cardiac parameters showed any differences relating to gender.
Some differences were noted with age, indicating that older horses felt more anxiety about the novelty than younger horses.
“Thoroughbreds and females had distinct correlations between behavioral and heart-rate variables in comparison with other groups, suggesting that escape duration might be a good indicator of stress, especially in these two groups.,” the study team said.
These results, they said, are expected to improve equine welfare, safety and utility, by providing insights into the temperament of particular horse groups, to better match reactivity levels with specific functions.
Discussing their findings, the authors noted that previous work by others regarding horse personality, as assessed by owners, revealed that Thoroughbreds were the most nervous breed, whereas ponies had a less nervous disposition. Warmbloods had an intermediate level of nervousness.
“Other previous studies concur with this. A study exploring horse temperament reported that Thoroughbreds were ranked highly in breeds showing high excitability and anxiousness. Another study demonstrated that ponies had lower anxiety scores than sport horses.
“The results of the current study concur with these studies in that Thoroughbreds had significantly higher behavioral scores than other horse breeds. Jeju crossbred horses had the lowest behavioral score in our study.”
They continued: “Our study identified clear differences between breeds in behavioral and cardiac parameters when responding to a novel stimulus.”
They noted that the temperament of Jeju crossbreds, derived from a Korean native pony, is rarely studied, despite their popular usage in Korea for horseback riding.
“The findings of this study will improve the prediction of sensitivity of responses of horses to novel objects based on breed, sex, or age. Horses can be matched on the basis of level of experience of the rider (less nervous horses more suitable for beginners) with the results, thus lowering the risk of horseback riding.
“These findings will contribute to efforts aimed at improving horse welfare and safety, while also providing means to increase the potential economic benefits.”
Behavioral and cardiac responses in mature horses exposed to a novel object
Kyung Eun Lee, Joon Gyu Kim, Hang Lee, Byung Sun Kim
J Anim Sci Technol 2021; 63(3):651-661, pISSN: 2672-0191, eISSN: 2055-0391, DOI: https://doi.org/10.5187/jast.2021.e51