Electricity and fuel use of aviary-laying hen houses in the midwestern united states

There is a growing interest in and movement toward alternative housing systems for laying hens. Associated with the movement are many questions to be addressed concerning sustainability of these systems. This study quantified electricity and propane use in two side-by-side aviary houses each with a holding capacity of 50,000 laying hens, located in Iowa. Electricity use was partitioned into different housing components, including ventilation, lighting, and manuredrying. Results indicate that electricity consumption for ventilation had the most variation, accounting for 30% of the total electrical demand in the summer but less than 5% in the winter. Manure-drying blowers ran continuously throughout the flock, using approximately 345 kWh d^-1 and accounting for approximately 51% of the annual electrical demand. Ventilation efficiency of the exhaust fans was approximately 25.5 m³ (h-W)^-1(15 CFM W^-1) at static pressure of 12.5 Pa (0.05 in. water column). Over the 15-month monitoring period, both houses had an average electricity cost of 3.0 cents per kg (or 2.3 cents per dozen) eggs produced (based on the rate of $0.09 kWh-1). The propane use was minimal, less than 425 L (112 gal) in one year or 0.6 mL per kg (0.4 L per dozen) eggs produced.