Ventilation rates in 329 livestock buildings in Northern Europe (England, The Netherlands, Denmark and
Germany) in winter and summer were estimated from a carbon dioxide (mass balance). On the basis of 500 kg liveweight, the mean ventilation rate across all countries was 341 m3/h for cattle, 241 m3/h for pigs and 451 m3/h for poultry during winter. The corresponding summer ventilation rates were 404, 428 and 965 m3/h (500 kg) liveweight, respectively. Recommended maximum ventilation rates in summer were not reached in some pig and poultry houses: the installed capacity may have been insuA