Effects of Cage Density on the Microenvironment and Health of Mice

Student Name: Jessica Ye
UCD Department: Anatomy, Physiology, and Cell Biology (Vet Med)
UCD Mentor: Dr. Kent Lloyd and Dr. Kristin Evans

According to the Institutional Animal Care and Use Committee (IACUC), Public Health Services (PHS), and Office of Laboratory Animal Welfare (OLAW), institutions must follow guidelines set by the Guide for the Care and Use of Laboratory Animals in their animal care and use programs when establishing mice populations within a cage to maintain the health and welfare of the laboratory mice2. The effects of mouse-caging density were studied in this project to determine the maximum number of mice that could be housed in a cage and maximum time between cage changes while maintaining the health and welfare of the mice. The CO2 level, Ammonia level, change in air flow, temperature, humidity, and any social, behavioral, or physical changes of the mice were evaluated. Seventy cluster of differentiation 1 (CD-1) outbred female adult mice were divided into four groups, with a minimum of two mice and a maximum of five mice per cage. Each week measurements of the microenvironmental gases in the cage, observations of the behavior and physical changes in the mice, cage temperature, cage humidity, cage airflow, and weights of the mice were recorded, for three weeks.