Dust Reduction in Broiler Houses by Spraying Rapeseed Oil

The effect of spraying rapeseed oil on the reduction of dust and ammonia concentrations and emissions, and on animal parameters was investigated in a dose-response study in a broiler house during three growing periods in four (round 1) or five rooms (rounds 2 and 3). The spraying rates varied per room, from 0 (control) to 24 mL oil m(-2) d(-1). Concentrations of PM10 and PM2.5 in incoming and outgoing air were measured. Production results (growth rate, feed intake, mortality rate) and foot-pad lesions were also determined. Regression analysis showed that a spraying rate of 6 mL oil m(-2) d(-1) reduced PM10 concentrations by 44% and PM10 emissions by 48%. At 24 mL oil m(-2) d(-1), the reduction was 82% for PM10 concentrations and 87% for PM10 emissions. For PM2.5, the lowest spraying rate of 6 mL oil m(-2) d(-1) was sufficient to reduce concentrations by 68% and emissions by 84%. The reduction achieved at higher spraying rates was not significantly greater. Emissions of PM10 and PM2.5 increased exponentially with the age of the broilers. A clear diurnal pattern was observed, with lower dust concentrations during the dark periods. Production results were unaffected by the spraying rate. A high rate of 24 mL oil m(-2) d(-1) increased the number and severity of foot-pad lesions. It is concluded that spraying rapeseed oil significantly reduces dust concentrations and emissions from broiler houses. To prevent adverse effects on broilers' foot-pad quality, it is recommended that the maximum rate should he 16 mL oil m(-2) d(-1).