02290nas a2200157   4500008004100000022002500041245021000066210006900276260001600345300002000361520163000381100002802011700002202039700002302061856004802084       2022                        eng d  a0023-6772, 1758-111700aThe use of ball pits and playpens in laboratory Lister Hooded male rats induces ultrasonic vocalisations indicating a more positive affective state and can reduce the welfare impacts of aversive procedures0 ause of ball pits and playpens in laboratory Lister Hooded male r  cJan-13-2022  a0023677221106593 a<p><jats p=""> The advancement and quality of science rely on research that is robust and unbiased in its experimental design, execution, analysis, and reproducibility. In preclinical research, a better understanding of animal emotions and refinement of their husbandry, housing, and handling are important goals in providing good animal welfare in a laboratory setting which underpins rigorous research quality. Induction of positive emotional state in animals is a key component of their well-being, and one approach is to increase their environmental complexity using, for example, ball pits or playpens in rats. In this study, we recorded 50&thinsp;kHz ultrasonic vocalisations (USVs) during animals&rsquo; exposure to the ball pit and playpen. We have previously shown that 50&thinsp;kHz USVs provide a graded and quantifiable measure of an animal&rsquo;s emotional state, and here find that access to the ball pit and playpen increases 50&thinsp;kHz USVs, indicative of a more positive affective state. Using our affective bias test (ABT) we next quantified the animals&rsquo; emotional response to an aversive intervention and whether this could be attenuated by access to a playpen. The playpen exposure completely mitigated the negative affective state induced by an anxiogenic drug when compared with animals who experienced the drug in the home cage. Together, these findings suggest ball pits and playpens provide a simple and effective method to improve the welfare of laboratory rats and reduce the cumulative suffering they experience from their housing conditions and minor, aversive procedures. </jats></p>
1 aHinchcliffe, Justyna, K1 aJackson, Megan, G1 aRobinson, Emma, SJ  uhttp://dx.doi.org/10.1177/00236772211065920