The fasting metabolism of adult wether sheep.

The heat produced when an animal is fasted in an environment which is neither too hot nor too cold to cause increases in metabolism is a measure of the energy needed to maintain that animal. When man is the subject, muscular repose can invariably be assured and the measurement of heat production is termed the basal metabolism. Most animals do not co-operate in the way that man does and their heat production during fasting thus includes some heat incidental to normal body movement. The measurement is, therefore, best termed the fasting metabolism. Many thousands of determinations of the basal metabolism of man have been made and have recently been reviewed in detail by Quenouille, Boyne, Fisher & Leitch (1951). No studies on any similar scale have been made of the fasting metabolism of sheep, though notable investigations have been made by Ritzman & Benedict (1930, 1931), Lines & Pierce (1931) and Marston (1948). In addition, Brody (1945) has made a number of determinations of heat production in sheep at various times after food. During the past 7 years, the fasting metabolism of adult wether sheep has been determined in this laboratory on many occasions during the course of other experiments and this paper is concerned with analysis of the results.