A Simplifiée! Method for Estimating the Rate of Oxygen Consumption of Young Chicks1

TH E various methods in animal calo-rimetry are reviewed in excellent dé-tail by Brody (1945). Of the methods which are suitable for young chicks the gravimétrie appears to be the most popu-lar. The gravimétrie method is tedious to operate, requires expensive equipment, subjects the expérimental animal to an unnaturally dry atmosphère, and requires a relatively long expérimental period per bird. The volumetric method as generally used employs the Regnault-Reiset ap-paratus or some modification of it. The Regnault-Reiset apparatus is complicated and expensive. Multiple chambers in this apparatus enable an operator to reduce the time required per animal in a given trial. The authors encountered the problem of making a large number of comparisons of the relative rates of oxygen consump-tion in chicks from day-old to 4 weeks of âge. I t seemed désirable to use inexpensive laboratory equipment and follow a simple but rapid routine in dealing with the individual chicks. The success of the Benedict-Roth-Collins clinical metabo-lism apparatus as a basis for estimating human basai metabolic rate (Houssay, 1951) and large animal resting metabo-lism (Brody, 1945) indicated the possibil-1 Part of a doctoral thesis présentée! by G. H