Development and consistency of fearfulness in horses from foal to adult
By J. Winther Christensen, C. Beblein & J. Malmkvist (2020)
Applied Animal Behaviour Science. Elsevier
Understanding the development and consistency of behavioural responses across life stages is of both fundamental and applied interest. In horses, fearfulness is particularly important because fear reactions are a major cause of human-horse accidents, and because fear is a negative emotional state with negative consequences for animal welfare and performance. In this study, we investigated the development and consistency of fear reactions in horses, from foal to adult. Twenty-five warmblood stallions of the same age, kept under the same conditions and with minimal human handling, were tested in novel object tests before weaning from the dam (at 5 months) and after weaning, at 1 year (two tests) and again at 3.5 years of age (two tests). Behaviour and heart rate responses were recorded. We found that foals’ expression of alertness towards novel objects was the best predictor of their later behaviour. Some changes in the expression of fear-related behaviour were evident pre and post weaning. Consequently, there were stronger correlations between the post-weaning tests, although these were further separated in time (2.5 years) than the 5 months and 1-year tests (7–9 months). Further, there were positive correlations in the horses’ reactions in the two tests at 1 year and at 3 years (e.g. heart rate: rs = 0.82, P < 0.001 and alertness: rs = 0.68, P < 0.001), suggesting that fearfulness is relatively stable across test situations at a certain age point. We conclude that it is possible to test for fearfulness at an early age (before weaning), by measuring the level of alertness towards novel objects. However, responses in post-weaning tests are more consistent. Our findings contribute to an understanding of the expression, development and consistency of fearfulness, which is advantageous for early assessment of behavioural differences in horses.