Clicker Training as an Applied Refinement Measure in Chickens.

Simple Summary: As part of a larger study, corticosterone levels in plasma and saliva as well as the assessment of behavior and fecal output in a New Area Test were used in chickens used for experimental purposes to investigate the possibility of mitigating the stress sensation, which is easily induced by handling and sampling by means of prior three-week clicker training. It was shown that this training is a suitable measure of cognitive enrichment in the sense of the 3R principle and that the first stress impulse at the beginning of the stress exposure can be attenuated. However, three-week clicker training is neither sufficient for a sustainable reduction in stress perception in prolonged stress situations nor for the sustainable strengthening of self-confidence and resilience. Further studies with longer training periods, more stressful situations, and additional parameters of stress assessment are warranted. When using chickens in animal studies, the handling of these animals for sample collection or general examinations is considered stressful due to their prey nature. For the study presented here, plasma and salivary corticosterone as well as New Area Test behavior and fecal output were used to evaluate whether it is possible to influence this stress perception using a three-week clicker training program. The results indicate that clicker training seems to be a suitable refinement measure in the sense of cognitive enrichment for the husbandry of this species. However, since it was also shown that three-week training was not sufficient to sustainably reduce the stress perception with regard to prolonged stressor exposure, and since it was also evident that manipulations such as routine blood sampling are perceived as less stressful than assumed, further studies with prolonged training intervals and situations with higher stressor potential are warranted. Also, further parameters for training assessment must be considered. For the general use of training as a supportive measure in animal experiments, its proportionality must be considered, particularly considering the expected stress and adequate training time. [ABSTRACT FROM AUTHOR]