Metabolic and behavioral measurement systems for facilitating the analysis of live subjects, including animals, comprising gas flow generators, analyzers and monitors; health monitoring apparatus and instruments for use in the measurement, monitoring, and analysis of metabolic activity in animals, comprised of gas analyzers, gas flow rate monitors, gas flow generators, gas manifolds, and channel switchers for animal mass measurement, food and water mass measurement, and controllers for monitors and management of gas concentrations, gas flow, air flow, temperature management, relative humidity management, and access to food and water, namely, measuring use of air, food and water intake and energy expenditure; live subject monitoring apparatus for laboratory and scientific research use, namely, monitors for collecting and analyzing behavioral data, namely, activity, exercise, position and movement within one or more chambers; laboratory equipment, namely, full body or partial body animal and human hoods, masks, cages, and chambers, and support racks, all for use in medical analysis of live subjects; instruction manuals packaged therewith, sold as a unit