ABS 2022
Multidisciplinary assessment of cumulative experience in laboratory rhesus macaques
Janire Castellano Bueno, Alexandra Paraskevopoulou, Letitia Sermin-Reed, Sam Groves, Nathan Kindred, Mathilde Jay, Aleksandra Czeszyk, Josephine Panafieu, Julie Safourcade, Susanna Carella, Chris Miller, Melissa Bateson, Colline Poirier. Newcastle University, Newcastle upon Tyne, North East, United Kingdom

Rhesus macaques are widely used in research. Welfare concern due to their extensive stays at research facilities is increasing and led to the introduction of the concept of cumulative experience (net impact of all events affecting the welfare of the animal over its lifetime). 
We assessed the cumulative experience of laboratory macaques and identified any impacting factors. We used new, validated behavioural (Inactive not alert) and neuroimaging indicators of cumulative experience, and traditional indicators of welfare (body weight and alopecia). We refined the behavioural indicator to maximise its sensitivity and specificity.

Neither the neuroimaging indicator nor the weight measures showed any signs of cumulative experience in the subjects. However, we found a small increase in alopecia and the frequency of the behavioural indicator over time, compared to other factors known to have a detrimental impact on welfare (i.e. single-housing). The data suggests that this latter effect is likely to be caused by experimental procedures. 

This is the first study revealing a cumulative negative effect of experimental procedures on laboratory macaques.