The modern domestic environment of the racehorse is much different from that of the wild habitat the horse once adapted to survive in. Prior to domestication, as a prey animal, horses relied on being vigilant to potential threats and having quick reactions to escape danger. The ‘fight or flight’ response is responsible for assessing and acting on possible threats. When animals encountered new, potentially dangerous situations they enter a state of stress in order to process and act accordingly. Some individuals may find the same situation more or less stressful, and for those that have heightened stress responses, chronic stress could negatively impact on several aspects of health.
Plusvital scientists, with researchers at University College Dublin, Ireland, measured the stress hormone cortisol to examine individual differences in stress responses of yearlings encountering the new training environment and milestone early training events. The research was part of a four-year PhD research project that investigated genetic contributions to behaviour in young racehorses and has been published in the peer-reviewed journal PLOS ONE.
Lead scientist, Dr Amy Holtby said, “This research provides scientific evidence to support the idea that horses have individual stress responses to the same situation and should be managed accordingly. We found that the greatest difference in the cortisol biomarker among yearlings was the first time they were backed.
“Currently trainers modify and adjust a horse’s training routine to best suit the individual needs of each horse. This approach could be fine-tuned with scientifically-developed biomarkers. Developing robust biomarkers for assessing horse welfare is a fundamental part of how we can best support the highest standards of welfare in racing”.