Volume I - Section I - Introduction 
Page I - 1 1 
Urease-Activating Properties of Commercial Laboratory Animal Bedding, 1981, Lab. Anim. Sci. 
31:56-59; H. Murakami: Differences Between Internal and External Environments of the Mouse 
Cage, 1971, Lab. Anim. Sci. 21:680-684. 
Ammonia production by bacteria can be influenced by the strain or stock of animal as 
well as by population density, relative humidity, temperature, and type of cage bedding. 
Strain, stock and sex differences in ammonia production have been shown with BALB/c 
mice producing less ammonia than CD1 mice. For mice housed in microisolator cages, 
ammonia concentrations were > 100 ppm for strains DBA and CD-I and approximately 
21 ppm for strain BALB/c on the 7th day of soiled bedding. 
R.G. Maghirang, G. L. Riskowski, L. L. Christianson, and P. C. Harrison: Environmental 
Management of Laboratory Animals, Research Needs, 1994, ASHRAE Transactions, V.100, 
Pt. 2, OR-94-16-1. 
Recognizing the research needs for laboratory animal facility design and management is 
important for both cost-effective design of laboratory research animal facilities and the 
reliability of laboratory animal experiments. The Laboratory Animal Consortium (LAC), 
which consists of representatives from various industries and organizations involved with 
laboratory animals, has identified the following five major research priorities: the effects 
of microenvironmental conditions on the response of laboratory rats, the means for 
achieving appropriate ranges of environmental conditions, the environmental preferences 
of rats, the relationships between cage and room environmental conditions in typical 
laboratory animal facilities and caging systems, and the practical methods for measuring 
cage environmental conditions. 
Recognizing the research needs for laboratory animal facility design and management is 
important for both cost-effective design of animal facilities and reliability of experimental 
procedures. The LAC, consisting of representatives from various organizations involved 
with laboratory animals, has identified five major research priorities: 
• Effects of micro environmental conditions on the heat, moisture, gas, and particulate 
production rates of rats; 
• Practical means for achieving appropriate ranges of environmental conditions; 
• Environmental preferences of rats; 
• Relationship between cage and room environmental conditions in typical laboratory 
animal facilities and caging systems; and 
• Practical methods for measuring cage environmental conditions. 
