Study on Odor in barn

Present condition of pig barn in respect of odor intensity

Abstract

Aiming at grasping the present conditions of a pig barn, odor intensities inside and around the barn were assessed at several time in summer and winter and the relationship between the odor intensity and other environmental factors was investigated on the pig barn.
Concerning the time-course changes in the odor intensity, the minimum level was detected in the winter season, however, the mean level was found to be higher in summer than in winter. And the odor intensity was highest around 16 o'clock both in summer (49Hz) and winter (53Hz). The obtained data on the odor intensity and the other environmental factors were analyzed according to the multiple regression analysis method and the odor intensity was found to be significantly correlated with those factors in the barn. Inside the barn the temperature of the barn, absolute humidity and wind velocity influenced the odor intensity and so the intensity was high under the climate conditions of high temperature and humidity, whereas around the barn, the effects of wind velocity were large. Therefore, the area of which odor level exceeds the recognition threshold concentration (RTC) is apt to be increased in the leeward and decreased in the windward as an increase in wind velocity. Further, the present results indicate that the relationship between the specific odor intensity (the specific odor intensities was given the odor intensities around the born by the mean level of the odor intensities inside the born) and the wind velocity varies depending on a wind direction and a distance from the barn.