A poultry transport trailer for poultry transport units, which trailer has a ventilation arrangement with ventilation devices and ventilation openings with forced ventilation, such as fans and ducts having openings, for ventilation of the poultry transport units. The ventilation arrangement on the trailer has ventilation openings registering with ventilation columns inside the poultry transport units. Following arrival at the slaughterhouse the poultry transport units remain on the trailer during lairage and the ventilation system is operated during lairage to ventilate the transport units inside out.