A new ventilation system to reduce temperature fluctuations in laying hen housing in continental climate.

Poultry suffer from large temperature variations with traditional tunnel ventilation and wet-pad evaporative cooling (TV) system in continental climates, which negatively influences production performance, resulting in significant economic losses. An ideal ventilation system is desired for retrofitted and new poultry houses. A new ventilation (NV) system was designed to mitigate the air temperature variations and improve the uniformity in poultry houses located in continental climate regions. The evaporative cooling pads were installed on both sidewalls and exhaust fans were located on a gable wall in the NV system. The system could be operated in different modes for daytime and night time by automatically running or not running evaporative cooling according to indoor set-point temperature. The performance of the NV system was evaluated in comparison with a TV system by measuring the thermal environment and layer performance of two commercial poultry houses with different ventilation systems. The results showed that the NV system provided a cooler air environment than the TV system, and the maximum fluctuation in average air temperature was reduced to 1 °C vs. 6.1 °C in TV system. Based on temperature-humidity heat stress index (THI) values, compared to the TV system, the NV system reduced heat stress time across the building in horizontal and vertical planes. The egg production was higher in the NV system house than in the TV system house (20.3% vs 18.9%), and the mean bird's mass in NV system house was 21 g higher than in TV system house. • Evaporative cooling pads of new ventilation system were installed in commercial house. • The new ventilation system provided a cooler air environment than the traditional system. • The new ventilation (NV) system reduced temperature-humidity heat stress index values. • Egg production was higher in the NV house than in the traditional system (TV) house. • The mean bird mass was 21 g higher in the NV house than in the TV house. [ABSTRACT FROM AUTHOR]