Evaluation of Bedding and Nesting Materials for Laboratory Mice by Preference Tests

Bedding and nesting materials can improve the health and environmental welfare of laboratory mice. This study was carried out to examine which items are actually preferred by mice. Two series of studies were performed on four types of floor-covering materials (Wood-shavings (Clean-chipTM), Cloth (AgrebeTM), Recycled-paper (Paper-cleanTM), Paper (Care-feeazTM)), and on four types of nesting materials (Recycled-paper (Shepherd-shackTM), Cloth (AgrebeTM), Wood (Wood-cylinder), and Polycarbonate (Mouse-iglooTM)). Preference of bedding materials was judged by the time length of staying in a cage. The results indicate that mice stayed in the cloth material (AgrebeTM) longer than in other bedding materials (light 51.1 ± 5.3%, dark 51.5 ± 2.6%). In the second experiment, the duration of stay in AgrebeTM was significantly longer than that in the other nesting materials in the light phase (70.9 ± 2.4%). In the dark phase, staying time both in AgrebeTM and Shepherd-shackTM were significantly longer. These data suggest that cloth bedding and nesting is recommended for the environmental enrichment of laboratory mice.