The distribution of water in the different body compartments of eight sheep of the Marwari breed was determined after imposing the following treatments: watering ad lib., restriction to 75%, 50%, and 25% respectively of normal daily water requirements (each treatment of 5 days' duration, with a 7-day normal drinking regime between treatments), and complete deprivation of water for 3 days. The total body water, the total blood and plasma volumes, and the extracellular, intracellular, and interstitial fluid volumes of the animals began to decrease when the water intake was reduced below 75% of the normal daily requirement. A reduction to 25% normal was similar in its effect to complete deprivation, at which the plasma volume fell by 43% and the extracellular fluid volume by 33%. The findings clearly point to an unusual ability of these animals to maintain circulation even when faced with considerable haemoconcentration.

The distribution of body water in the different body compartments of four highpotassium (HK) and four low-potassium (LK) type sheep of the Marwari breed of the Rajasthan desert was determined after imposing the following watering treatments, viz. watering ad lib., J, J and § restrictions (each of five days' duration with a sevenday normal drinking regime between each treatment) and water deprivation (of three days' duration). There was no difference in the voluntary water intake of the HK and LK animals. The HK animals normally have a higher blood and plasma volume status than the LK. In both types of animals, the total body water, total blood and plasma volumes and the extracellular, intracellular and interstitial fluid volumes started decreasing as water intake was reduced below 25 % of the daily requirement. In both the phonotypes 75 % reduction was similar in its effect to complete deprivation. The physiological status of the HK Marwari animals appears to be somewhat superior to that of the LK although both types seem to be equally adapted to the conditions of the habitat.