Numerical Simulation of Airborne Disease Spread in Cage-Free Hen Housing with Multiple Ventilation Options

Long Chen; Eileen E Fabian-Wheeler; John M Cimbala; Daniel Hofstetter; Paul Patterson

doi:10.3390/ani12121516

Numerical Simulation of Airborne Disease Spread in Cage-Free Hen Housing with Multiple Ventilation Options

Animals (Basel). 2022 Jun 10;12(12):1516. doi: 10.3390/ani12121516.

Authors

Long Chen^{1

2}, Eileen E Fabian-Wheeler¹, John M Cimbala³, Daniel Hofstetter^{1

4}, Paul Patterson⁵

Affiliations

¹ Department of Agricultural and Biological Engineering, The Pennsylvania State University, University Park, PA 16802, USA.
² Tianjin Academy of Agricultural Sciences, Tianjin 300384, China.
³ Department of Mechanical Engineering, The Pennsylvania State University, University Park, PA 16802, USA.
⁴ Department of Agricultural and Biological Engineering, University of Florida, Gainesville, FL 32611, USA.
⁵ Department of Animal Science, The Pennsylvania State University, University Park, PA 16802, USA.

Abstract

The current ventilation designs of poultry barns have been present deficiencies with respect to the capacity to protect against disease exposure, especially during epidemic events. An evolution of ventilation options is needed in the egg industry to keep pace with the advancing transition to cage-free production. In this study, we analyzed the performances of four ventilation schemes for constraining airborne disease spread in a commercial cage-free hen house using computational fluid dynamics (CFD) modeling. In total, four three-dimensional models were developed to compare a standard ventilation configuration (top-wall inlet sidewall exhaust, TISE) with three alternative designs, all with mid-wall inlet and a central vertical exhaust. A one-eighth scale commercial floor-raised hen house with 2365 hens served as the model. Each ventilation configuration simulated airflow and surrogate airborne virus particle spread, assuming the initial virus was introduced from upwind inlets. Simulation outputs predicted the MICE and MIAE models maintained a reduced average bird level at 47% and 24%, respectively, of the standard TISE model, although the MIRE model predicted comparable virus mass fraction levels with TISE. These numerical differences unveiled the critical role of centrally located vertical exhaust in removing contaminated, virus-laden air from the birds housing environment. Moreover, the auxiliary attic space in the MIAE model was beneficial for keeping virus particles above the bird-occupied floor area.

Keywords: airborne disease; cage-free hen housing; computational fluid dynamics; numerical simulation; ventilation system.

Grants and funding

This research was funded by the Egg Industry Center (EIC) and USDA National Institute of Food and Agriculture Federal Appropriations under Project PEN04614 and grant number 1011207. The APC was funded by the Department of Agricultural and Biological Engineering at Pennsylvania State University.