An experiment was performed to investigate the energy efficiency and effect of poultry house size on energy productivity in 3 different capacity management systems. Capacities of houses were 10000(3 housings), 20000 (2 housings) and 28000 (1 housing) birds per production period and were assigned as HI, HII and HIII respectively. This experiment was conducted in a completely randomized design applying a nested pattern. Utilized energy in the form of fuel, electricity, feed, labour, wood shaving, chicks and utilized chemical as inputs and litter and broilers as outputs were measured in each production period. Result showed that inputs significantly decreased with increasing the size of poultry house from HI to HIII. A significant difference (P<0.01) in energy indexes was observed across the three capacities of housing investigated. Thus division input energy and cost in production of HIII exhiited better productivity than the other units in this study. تفاصيل المقالة