Each animal was weighed daily inside his or her respectivemetabolic
cage using a Slater 500 kg balance. A hydraulic jack connected to the
balance lifted them. This system was periodically calibrated with
weighed bags of sand and was found to have an accuracy of ±1.0 kg.
Animals were weighed at the same time daily (usually at 0900 h)
throughout the experimental treatments.
For the water deprivation (dehydration) phase of the experiments,
the animals were provided with graded restricted amounts of water
until they had lost 15% of their initial body mass. Itwas assumed that this
level of dehydration would cause maximal stimulation of physiological
mechanismforwater conservation.Waterwas then given at a level that