Daily carbon dioxide emission and activity of rabbits during the fattening period

Carbon dioxide balance is a powerful tool for determining ventilation rates in animal buildings. Accurate values for carbon dioxide emissions from animals and the daily variation of these emissions are required to work with these balances. Traditionally, the daily variation of carbon dioxide has been related to daily patterns of animal activity. Little information is available about carbon dioxide emissions from fattening rabbits. Carbon dioxide emissions from 21 fattening rabbits were measure throughout the fattening period. Emissions from each single animal were monitored during 24 h, using a flux chamber. Ten of these rabbits were monitored by video and their activity was assessed for the 24-h periods. Results showed an average carbon dioxide emission rate per rabbit of 1.98 ± 0.72 L h−1, for an average weight of 1240 ± 412 g. An exponential relationship between animal weight and carbon dioxide emission was observed. Sinusoidal daily patterns of carbon dioxide emission and relative animal activity were determined and described using equations. A positive relationship between carbon dioxide emission and relative animal activity was observed, although differences in the amplitude of the curves were found: 16% of the average value for carbon dioxide emission and 41% for relative activity.