An apparatus and technique for measuring the respiratory exchange of fed sheep over periods of forty-eight hours

Abstract

The gaseous exchange of the sheep can be measured in the apparatus described with considerable accuracy and good agreement obtained with the energy absorbed from a maintenance diet. The apparatus automatically compensates for diurnal changes in temperature and humidity, and maintains a constant rate of ventilation.The precautions necessary to ensure that the metabolism as measured is a good sample of that of the animal when subsisting on the diet, consist of control of temperature and humidity within the chamber and training the animal so that it is free of psychic strain during the period of measurement. It was found that the sheep takes 14–20 days to adjust its energy turnover to a change in diet.Modification in structure and operation of the Haldane-Carpenter gas analysis apparatus are described in detail.The method of A. C. Andersen is used to compute the energy metabolism and respiratory quotient from the gaseous exchange and methane production.