Sprinkling system in cage-free henhouse
Dust suppression with the sprinkling system in cage-free henhouse
The cost-effective water sprinkling system tested by Dr. Lilong Chai, a poultry engineering specialist in UGA poultry science department, could suppress up to 50% of the dust levels in the commercial cage-free henhouses without causing ammonia issues.
Concerns over animal welfare have led to pledges of sourcing only cage-free eggs by many U.S. food retailers and restaurants. According to the current number of pledges, it would take more than 70% of the current US layer inventory or over 230 million layers to meet the pledged demand by 2025 or 2030. However, cage-free housing poses many environmental challenges, such as high particulate matter or dust levels. Dust levels in cage-free hen houses are 6-9 times higher than conventional cage system due to hen activates (e.g. dustbathing or foraging) on litter floors. Higher levels of dust can carry more airborne microorganisms which, once inhaled, may cause infection or trigger respiratory diseases to animals and/or their caretakers. Therefore, mitigating dust generation in cage-free henhouses is imperative to protecting the health and well-being of the animals and the caretakers; and mitigating the emissions of dust to environment and ecosystem.
Dr. Lilong Chai, a poultry engineering specialist in UGA poultry science department, is studying an engineering method for dust suppression in cage-free henhouse. A sprinkling system was designed for spraying water on litter floor of cage-free house. The best spray dosage based on litter depth was identified during the lab-scale and a field verification study in a commercial cage-free henhouse. In addition, the system was applied to reduce heat stress of birds by spraying water on birds directly in hot weather.
The sprinkling system Dr. Chai tested could suppress up to 50% of the dust levels in the commercial cage-free henhouse without causing ammonia issues. For the heat stress relief, the body surface temperature of hens was reduced by 12-13 °F immediately after water spraying in summer. This study was the first to spray water for dust suppression in commercial cage-free house in the USA. The cost of dust suppression system Dr. Chai tested is about $0.05-0.1 per bird per year, which is over 70% lower than most existing dust suppression methods such as electrostatic precipitator and dry filter.