SUMMARYApparatus and technique for the determination of the oxygen consumption and of the carbon-dioxide production of the calf during periods of 30 min. are described. The apparatus is based on that of Tissot (1904), the chief modifications being the considerable increase in its size and the inclusion of a flexible counterpoise for the bell. When a calf is affected by acute infantile diarrhoea, 'scouring', there is a marked fall in the amount of nutrients it absorbs from its digestive tract. This is sufficient to cause such negative nitrogen and energy balances that in many severe cases the calf is very close to a state of complete inanition. In farm practice a common and effective method of controlling this type of diarrhoea is to substitute boiled water for the normal milk allowance until the faeces become normal in appearance and then to commence realimentation very slowly. Such a method of control has the effect of substituting complete inanition for the partial inanition that results from diarrhoea. It is of some interest therefore, to study the metabolism of the calf during periods of starvation, and this paper is concerned with experiments designed to study nitrogen, sulphur, energy and mineral metabolism during short periods of starvation. Much has been published on the effect of starvation on mature animals, especially man, but comparatively little study has been made of the effect of starvation on the metabolism of the really young animal. In the mature bovine, energy metabolism has been studied by Braman (1924), Benedict & Ritzman (1927) and Ritzman & Benedict (1938), and extensive studies of the N metabolism of the fasting steer or cow have been made by Carpenter (1927) Brody (1932), Ritzman, Washburn & Benedict (1936), Blaxter (1948 and Marston (1948
REFIRENCIS
Brody, S. (1945).
Calves and their treatmentTwo Ayrshire bull calves were each subjected to two periods of starvation. The original plan was to study starvation and recovery in each animal when at a normal weight for its age and also following a period of undernutrition when its weight would be only 50 % of that which could be expected for its age. The object of such a design was twofold. Firstly, scouring in calves tends to be chronic before an acute stage is reached, and thus undernutrition for a period of time before almost complete inanition is a common phenomenon. A study of inanition following undernutrition, therefore, seemed desirable. Secondly, it has been shown by ,Marston (1948) that the minimal level of metabolism is reached more quickly when animals are starved following low levels of food intake than when starved following long periods of overnutrition or optimal nutrition. This may be related to the concept of a minimal base level of heat production (Forbes & Kriss, 1932; Forbes & Swift, 1941) and obviously is of considerable importance. Unfortunately one calf (no. s) became ill during the course of the pre-starvation period for the low plane of nutrition experiment and this experiment was abandoned. The animal on slaughter...
