1. Department of Animal Behaviour and Welfare, Institute of Genetics and Animal Biotechnology, Polish Academy of Sciences, 05-552 Magdalenka, Poland
2. The Research Station of the Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Popielno, 12-222 Ruciane-Nida, Poland
3. Unité Physiologie de la Reproduction et des Comportements, Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement, Centre National de la Recherche Scientifique, Institut Français du Cheval et d’Equitation, F-37380 Nouzilly, France
4. Animal Behaviour & Welfare Research Group, Department of Biological Sciences, University of Chester, Chester CH1 4B, UK