Abstract: A poultry raising system includes a house having one or more enclosed sections with at least one section provided with a plurality of hovers and all of the sections having peripheral heat assemblies. All hovers and heat assemblies are equipped with sealed heat radiating conduits supplied with a fluid heat transfer medium from a common heating apparatus. A supply and return line serving each section from the heating apparatus includes a thermostatically-controlled valve admitting the heat transfer medium to all of a section's hovers as well as other thermostatically controlled valves regulating the flow of heat transfer medium to each of a section's peripheral heat assemblies. Dampers in roof-top vents are automatically opened and closed in response to signals from a gas sensor in each section to evacuate obnoxious gasses from each section enclosure and the evacuated gas is replaced by fresh outside air admitted through automatic dampers adjacent the house side walls.