Abstract: A gear drive fan for ventilating and cooling structures used for containing livestock. The gear drive fan comprises a livestock structure having a roof and supporting members, where the roof is connected to the supporting members, a fan assembly, and means for attaching the fan assembly to the structure. The fan assembly comprises a blade assembly having a plurality of blades and a drive hub, a housing, a first electrical motor having a drive shaft, and a gearbox having a drive end and a hub end. The drive end of the gearbox is adapted to be closely coupled to the drive shaft of the motor, while the hub end is adapted to be closely coupled to the drive hub of the blade assembly, so that the motor and gearbox may be conveniently mounted to the blade housing or contained within the blade housing.