A respiration chamber for cattle.

Traditional methods for measurement of gas exchange in domestic animals utilize the open-circuit principle in which a known flow of air is drawn past the animal and its change in composition is measured; or the closed-circuit principle in which. carbon dioxide is absorbed and weighed and oxygen is metered into the system. The open-circuit chamber has an exact counterpart in a mask method and the closed-circuit chamber an approximate counterpart in a mask-spirometer method. A third principle in which the system is completely closed and there is no oxygen inflow or carbon dioxide absorption, but in which change in air composition is measured, was used for pigs by Charlet-Lery ( 1958). This “confinement” principle has been adopted by us for application to cattle.