Profile of Volatile Fatty Acids in Suspended Particulate Matter from a Poultry House Using Rice Hulls as Bedding Materials.

Livestock operations have long been associated with unpleasant odors whether it is a swine, poultry, or dairy operation.  Unpleasant odorous smell has been generally accepted as part of livestock operations in the past.  However, as more and more animal production continues to evolve into major concentrated operations, odor emissions from these confined animal feeding operations (CAFOs) have caused persistent public concern and complaints.  In addition, particulate matters and other gas emissions have also been a cause for environmental and health concerns.  Therefore, a thorough understanding of air emissions from CAFOs is a first necessary step in formulating effective management strategies for dealing with these odor and air quality issues.  In this study, the examination and characterization of volatile fatty acids (VFA), major components of odors from poultry operations, in suspended particulate matter (SPM) from a broiler house were carried out using particle trap impactors. The SPMs from the particle trap impactors were extracted and analyzed for its VFA contents using high pressure liquid chromatography (HPLC).  The results showed that proprionic acid and iso-butyric acid are the major VFA found in the SPM collected from the broiler house.  Their concentrations ranged from zero to 34 % by mass (VFA/SPM).  Trace amounts of other VFA (i.e., acetic acid, pentanoic acid, and hexanoic acid) were also observed from SPM analyses.  The concentration profile of VFA appeared to reach a maximum at the middle of the flock age (e.g., when the birds reach about four to five-week old) and tapering off toward the end of the flock age.