Emotional response of young race horses to a transfer from a familiar to an unfamiliar environment.

The aim of this study was to measure emotional arousal in young race horses as expressed by heart rate (HR) during routine situations of grooming, hoof cleaning, and while at rest, having been transported from the environment of home stud farm to that of an unfamiliar training centre. A hypothesis was developed that the change of environment is a source of heavy stress for young race horses. The investigation involved 22 Purebred Arabian stallions and 19 Purebred Arabian mares, 2.5 years old, and 11 Thoroughbred stallions and 10 Thoroughbred mares, at the age of 1.5 years. The horses were examined twice: first in their home stud farms, and then three days after being moved to an unfamiliar training centre. The HR was measured at rest and while the horses were being groomed in their boxes. The HR registered during the grooming session at the new stable increased significantly in all studied groups of horses compared to the data obtained at their home stud farm. This increase was significantly higher in the groups of 1.5-year–old Thoroughbred stallions and mares than in the groups of 2.5-year-old Purebred Arabian horses. Young race horses should not be groomed just before training because the grooming routine involves their emotional arousal.