Operation of an Air Filtration Device Results in Morbidity and Mortality in Growing Chickens (Gallus gallus domesticus)

Environmental conditions may influence experimental outcomes in laboratory animals. In this study, we measured the effects of a vortex air-filtration device (AFD) on growth rate, morbidity, mortality, behavior, and gross pathology in P2a Leghorn chickens (Gallus gallus domesticus) raised from hatchlings to 6 wk of age. Growth rate was reduced in the group exposed to the operating AFD ('AFD on' group) compared with the 2 control groups ('AFD off' and 'Historical' groups). Similarly, 6-wk survival probability and body weight were decreased in the AFD-on group compared with controls. Splenic and cardiac weight indices were lower in the AFD-on and AFD-off groups compared with the Historical group. A progressive increase in the ambient sound level (Historical, 53.5 ± 1.7 dBA; AFD off, 63.6 ± 0.5 dBA; AFD on, 71.8 ± 0.8 dBA) was the only variable found to correlate with the physiologic differences observed across the 3 groups of growing chickens. These findings indicate that experimental outcomes with growing chickens are negatively affected by vortex air-filtration devices.