Abatement of Particulate Matter Emission from Experimental Broiler Housings Using an Optimized Oil Spraying Method

In this follow-up study, we investigated effects of two rapeseed oil application rates (8 or 16 mL m-2 d-1) in combination with two spraying frequencies (daily or every other day) in four oil treatments: 8 mL m-2 (24 h)-1, 16 mL m-2 (48 h)-1, 16 mL m-2 (24 h)-1, and 32 mL m-2 (48 h)-1 during two growth cycles of broilers. Oil treatments were randomly assigned to four rooms, whereas two rooms served as control (0 mL m-2). Oil spraying started on day 21. Prior to the second growth cycle, the spraying system was optimized to improve the distribution of oil and reduce the generation of small oil particles. We measured ventilation rate and concentrations of PM10, PM2.5, ammonia, and odor. Furthermore, we recorded bird performance and birds' exterior quality. PM10 emission was significantly reduced by 59% at 8 mL m-2 d-1 and by 64% at 16 mL m-2 d-1. For PM2.5, these values were 81% and 74%, respectively. In the two every other day treatments, PM10 emission was 44% higher on days after spraying than on spraying days. No significant effect of oil spraying was found on ammonia emission, odor emission, bird performance, and birds' exterior quality. The latter finding confirms that the incidence of foot-pad lesions is not increased at an application rate of 16 mL m-2 d-1. It is recommended to validate the effects of oil spraying inside full-scale commercial broiler houses at a daily application rate of 16 mL m-2 or less.