Each animal was weighed daily inside his or her respective metabolic 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 mechanism for water conservation. Water was then given at a level that