Abstract
The present study aimed to evaluate the effects of self-loading training on the overall stress response during pre-slaughter transportation in slaughter horses. Thirty-two slaughter horses were divided into two groups: the control group (CG) and the Trained Group (TG). For six weeks, the TG horses were trained to self-load using a method based on target training and shaping. Animals from both groups were transported to the same slaughterhouse in small groups on different days using the same truck along the same route. The baseline and post-transportation values of the eye temperature and fecal cortisol metabolites were determined for all the animals. All the horses were video-recorded while being transported and unloaded. The horses' behavior was analyzed using a focal animal sampling method. During transportation, the presence of head shaking, licking, and chewing was significantly higher in the CG than the TG. During unloading, walking forward tended to be more frequent in the TG. The fecal cortisol metabolites and eye temperature were higher after transportation than at the baseline, but no differences between the groups were found. Overall, the results confirm that transportation for less than one hour caused detectable stress in slaughter horses. Based on these results, self-loading training appears to be somewhat useful to mitigate the overall transport stress.