The purpose of the study was to specify and evaluate half-bred and Arabian horses’ behaviours tested for racing performance on the Wroclaw – Partynice Racecourse in the 2006 season. 74 half-bred horses (42Malopolska breed, 8Wielkopolska breed, 24 PolishWarmblood) as well as 69 PurebredArabian horses which participated mainly in flat races were evaluated on a scale of 1 to 4. The behaviour was evaluated during taking horses round a paddock, at the time of mounting them by riders and during coming into a starting machine. Differences in the behaviour of the horses dependent on coaches, gender and the number of races were indicated. Moreover, relationships between examined factors and the individual success coefficient (ISC) were calculated. The most stressful activities were the following: coming into a starting machine and taking round a paddock, whereas the least stressful activity was mounting. It has been proved that mares are more stress-resistant than stallions. Negative correlations between the evaluation of horses’ behaviour at the paddock and individual success coefficient in PurebredArabian horses and Malopolska breed indicate that horses of these breeds strongly manifest pre-starting stress. High marks for behaviour correlated with more frequent participation in races prove that horses easily adapt to stressful conditions.

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