Aviary rearing system for commercial layers which optimizes the development of pullets destined for transfer to aviary layer production houses. The system is designed around the needs of the young birds as well as the working environment of the poultry farmer. At the start of the rearing cycle birds are housed in the system at an easy controllable level. The birds gradually learn to jump within the system encouraged by slowly increasing the height difference between feed and drinking lines and via winchable platforms.