Analysis of Individually Ventilated Cage (IVC) Microenvironments During 21-d Cage Change Frequency for Mice Using Two...

Area of Science:

• Laboratory animal science
• Animal welfare research
• Vivarium management

Background:

• Current guidelines recommend 14-day cage changes for rodent caging.
• Individually ventilated cages (IVCs) allow for performance-based extensions of cage change frequencies.
• Paper pulp cellulose bedding shows potential benefits over traditional corncob bedding.

Purpose of the Study:

• To compare the impact of paper pulp cellulose and corncob bedding on mouse IVC microenvironment.
• To evaluate extending cage change frequency from 14 to 21 days for mouse IVCs.
• To assess animal welfare and microenvironmental parameters under different bedding and change frequencies.

Main Methods:

• Comparison of paper pulp cellulose and corncob bedding in mouse IVCs.
• Assessment of ammonia levels, temperature, and humidity over 14- and 21-day periods.
• Monitoring of urine latrine size and overall animal condition.

Main Results:

• Ammonia levels, temperature, and humidity remained acceptable for 21-day changes with both bedding types.
• Paper pulp cellulose bedding resulted in significantly smaller urine latrine sizes compared to corncob bedding.
• Overall animal condition did not necessitate earlier changes within the 21-day period for either bedding type.

Conclusions:

• Extending cage change frequency to 21 days is feasible for mouse IVCs with either paper pulp cellulose or corncob bedding.
• Paper pulp cellulose bedding may be advantageous due to reduced urine accumulation.
• Further evaluation of early cage change criteria may be needed for corncob bedding to manage urine latrine size.