Corgan, Megan, authorGrandin, Temple, advisorBlack, Jerry, committee memberRollin, Bernard, committee member2021-06-072021-06-072021https://hdl.handle.net/10217/232537It is dangerous for both riders and horses when a horse suddenly startles. Sometimes horses do this in familiar environments with a possible cause being that familiar objects may look different when rotated. The purpose of this study was to determine whether horses that had been habituated to a complex object (children's plastic playset) would react to the object as novel when it was rotated 90 degrees. Twenty young horses were led past one side of the playset 15 times by a handler. Horses in the rotated group were led past the rotated playset 15 times, while the control group continued to be led past the playset in its original position. The behavioral signs observed and analyzed were ears focused on the object, nostril flares, neck raising, snort, avoid by stopping, avoid by moving feet sideways, and avoid by flight. The most common reactions observed were ears focused on the object, nostril flares and neck raising. Reactions were mild because the horses used were safe to lead and all procedures were done at a walk. When the playset was rotated, the behavioral signs observed were similar to behaviors exhibited during the first exposure to the playset. A two- sample t test was performed on the reactivity scores that compared the number of behavioral signs present on pass 1 compared to pass 16 by the rotated object. The horses in the rotated group reacted to the rotated orientation similarly to the first exposure (p = 0.0014, a < 0.05). Two-sample t-tests were conducted for corresponding passes 2-15 for the novel object to rotated object. There was little consistent association for the corresponding passes, showing the effect of the unpredictability of the horse. Awareness of potential reactions to changes in the orientation of previously familiar objects can help keep the handler safer. Horses' reaction to a rotated orientation of a familiar object and reduction in reaction over time will be similar to their original exposure.born digitalmasters thesesengCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.habituationnovel objecttraininghorsebehaviorsafetyText