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Johns Hopkins Bloomberg School of Public HealthCAAT

Animal Welfare Enhancement Awards - 2005 Recipients

Providing Enrichment Tools to Rodents that are Food-chewers
Chrystal Nelson, LAT
 University of Michigan

Some laboratory mice grind up their food pellets, and let them fall into the bedding. At our institution, we call mice with this behavior "food-chewers." Food-chewers create extra work for technicians because the ground-up food increases the amount of bedding in the cage, requiring more frequent cage changes. This increased bedding can also contact the sipper tube portion of the water bottle, causing it to leak and flood the cage. Ground-up food can also block airflow into cages that feature intra-cage ventilation, decreasing the fresh air exchanges that mice should receive. This behavior is probably stress related, and these mice may need to have more psychological enrichment tools to help reduce this atypical behavior. Mice that are distressed provide unreliable research data; having consistent and accurate data is very important for medical research projects, and many lives depend upon it. The objective of this study is to determine if offering chew toys and cellulose/corncob-bedding mixture as enrichment tools can reduce the food-chewing behavior in mice. The chew toys are nylabones designed for rodents. The cellulose/corncob bedding mixture is designed to have mice separate the two ingredients, as they will make a nest out of the cellulose. Food-chewers provided with the enrichment tools will hopefully not be obligated to waste the food pellets. This will decrease animal distress so that reliable data will be obtained for the laboratory researchers. Reduced food-chewing behavior will also make the technician's job easier; labor will be reduced and services will be more cost effective.