Two types of spatially enhanced caging systems were developed and evaluated for high-density housing of laboratory rats. Type 1 had L-shaped interior partitions and type 2 had platforms mounted on the sidewalls. The microenvironmental conditions and rat response in these caging systems were evaluated and compared with standard barren cages at standard population densities. Rats preferred type 1 over type 2 and over a standard barren cage. A 16-week evaluation did not show any significant difference between rats raised in type 1 cages and those raised in standard barren cages.

KEYWORDS: laboratory animal housing, calculating, microclimate, comparing, density, designing, ventilation, temperature, humidity, air, speed, contaminants, thermal comfort