New Systems of Ventilation and Environmental Control in Dairy Barns

Abstract

Dairy barn ventilation is more evolutionary than revolutionary. Changes in the management of the ventilation system have been as significant as the changes in hardware. The changes discussed are based on our experience with warm tie stall dairy barns of both new and old two story construction which are the predominant dairy housing used in Ontario. The major change in tie stall dairy barn ventilation has been the lowering of the barn temperature. With the increased ventilation rate, pathogen and gas levels are significantly lowered. In some situations, recirculation can improve distribution of air within the barn if a cross ventilation system is inadequate. Heat exchangers are a good source of supplemental heat but must be evaluated against other sources of heat on a cost recovery basis to justify them. Finally, the enthusiasm the swine farmers have had for natural ventilation has spilled over to tie stall dairy barns. Several new and retrofitted old barns have gone this route recently and it seems to be a continuing trend.