Building a strong relationship between humans and horses is crucial for safe and effective horse management. The results of an exciting new study published in the Journal of Equine Veterinary Science showed that serotonin, a chemical in the brain linked to mood and social behavior, plays a key role in how horses interact with people (Kim et al., 2025).
The study found that adding soybean oil to horse diets boosts serotonin levels, making the horses more friendly and open to human interaction.
The study found that adding soybean oil to horse diets boosts serotonin levels, making the horses more friendly and open to human interaction. It also helps manage stress by keeping cortisol levels stable and improving other stress markers. Friendlier and calmer horses is something we can all appreciate!
It’s well known that diet affects horse behavior, so, by adding fats like soybean oil to their diet (instead of starch), we have the ability to help reduce their stress, as well as some of the challenging behaviors that accompany stress.
While more research will help us better understand how these fats work, and their long-term effects, the findings from this study highlight the potential of dietary changes for improving the welfare and performance of horses.
Reference:
Kim, S., Choi, Y., Kim, J., Wickens, C., Yoon, M. (2025) Soybean oil supplement induces increased approaching behavior to humans and alters serotonin concentrations in horses, Journal of Equine Veterinary Science, Volume 146,105361, ISSN 0737-0806, https://doi.org/10.1016/j.jevs.2025.105361.
If you would like some help deciphering your horse’s behavior, reach out to Helena, she’d be happy to consult with you!