A New Method for Estimating the Heat Production of Animals

A new type of respiration chamber is described which avoids the need for absorption of carbon dioxide or for the measurement of large gas flow rates. The system is an extension of the ‘confinement’ principle for the measurement of respiratory gas exchange. The chambers are large enough to accommodate an adult cattle beast, but sufficiently flexible in operation to be used with individual sheep. Operation of the system is fully automatic, and information is recorded on the paper tape output from data logging equipment. The day‐to‐day variation in heat production by pairs of sheep kept in one chamber for periods of from 3 to 5 days was assessed; the coefficient of variation for heat production was 3 per cent.