Throughout the winter season, temperatures in the
rearing houses before and during transfer must be
adjusted to those in the production houses. Moreover,
to avoid temperature stress in wintertime, it is advisable
to preheat the production houses up to 18°C before
transferring point of lay pullets and to respect minimum
ventilation (cf. Ventilation part) requirements to avoid
damage caused by high CO² and NH3 levels. It is however
preferable to go down in temperature than to go up in
CO2/ NH3 levels. If necessary, use heaters.