An oil sprinkling system has been designed to control dust levels in pig buildings using undiluted crude canola oil and was previously tested over a two-week period. The system was tested again over a seven-week period to simulate a complete growth cycle. The application rate was optimized by reducing the oil application rate compared to previous experiments and by not sprinkling operator walkways. The dust mass concentration was reduced by 87% comparing the oil treatment to the control room and inhalable (>0.5 micro m) and respirable (0.5 to 5.0 micro m) dust particle counts were lowered by 90 and 86%, respectively. Compared with oil application rates recommended by Zhang et al. (1996), similar dust reduction results were obtained with a 36% reduction of the total oil usage (18.5 L compared to 29.0 L of canola oil) applied over the seven-week period. The system was effective in replicating previous dust reduction data collected with automated and manual systems and can be used to control dust levels in growing-finishing barns.