The experiment was conducted at Aftab Bahumukhi Farm Ltd (ABFL), Bhajitpur, Kishoregong, Bangladesh. The information regarding flock depletion, egg production performance, losses of eggs during hatching and post hatchery performance were collected from the record register of the farm which covered the period from August 2000 to November 2001. Male-female ratio of pad cooling, open-sided house and contract farmer's house was 1:7, 1:8 and 1:10, respectively.
Types of housing system and environment The parent stock (Arbor Acres) was reared in three different systems i.e. Pad cooling / Control house, Open-sided house and Contract farmer's house.
Pad cooling / Environmentally controlled house: This system of housing is usually adopted in hot and humid zones and is efficient for maintaining the proper temperature. The average temperature was maintained at 27°C during the rearing period. Open-sided house: Insulated roofing materials were used here. The average temperature during the rearing period was 30°C. Contract farmer's house: The contract farmer's house was similar to some extent to an open-sided house.
The overall temperature during the experimental period was 20-33°C. Provided that the satisfactory level of relative humidity for Arbor Acres is 60 - 65 % but observed relative humidity level was 55 to 80 % in open-sided houses and contract farmer's shed. In pad cooling houses, it was possible to maintain appropriate humidity. In terms of ventilation, in the pad cooling houses, it was possible to remove excess heat, moisture and dust. In the open-sided houses and farmer's shed air control was not required, however, fans were used in all of the houses. The floor of all houses was covered with rice husk.
Feeding Management The Arbor Acres were fed with different types of rations viz. pre-breeder diet, breeder diet I and breeder diet II for female birds and breeder diet male for male birds. The feeds were supplied in the form of pellets.
The pre-breeder diet was supplied to female breeders from 20 to 27 weeks, breeder diet-I from 27 to 35 weeks and breeder diet-II from 35 to the end of the experimental period, while the breeder diet for males was supplied to the male breeders from 24 to 64 weeks of age. Pure drinking water was supplied ad libitum to the birds to fulfill their requirements.
Lighting management Light was provided for 23 to 24 hours of the first 3 days of the chick's life for the habituation of eating and drinking in their new environment.
Statistical analysis The data on different parameters were analyzed with the help of MSTAT-C software on a computer. DMRT (Duncan's Multiple Range Test) was performed to observe the level of significance.