An ASABE Conference Presentation Paper Number: ILES12-1769 Airborne Particles in Animal Houses Huong T. L. Lai (PhD candidate), Wageningen UR Livestock Research, Lelystad, The Netherlands, Adaptation Physiology Group, Wageningen University, Marijkeweg 40, 6709 PG Wageningen, The Netherlands, Veterinary Medicine Faculty, Hanoi University of Agriculture, Vietnam, email: ltlhuongty@yahoo.com or lai.tl.huong@gmail.com . André J. A. Aarnink (Ph.D.), Wageningen UR Livestock Research, Lelystad, The Netherlands, email: Andre.Aarnink@wur.nl . María Cambra-López (Ph.D.), Institute of Animal Science and Technology, Universidad Politécnica de Valencia, Cno. de Vera s.n. 46022. Valencia, Spain, email: macamlo@upvnet.upv.es . Thuy T. T. Huynh (Ph.D.), Nong Lam University HCMC Vietnam, email: huynh.t.t.thuy@gmail.com . Henk K. Parmentier (Ph.D.), Adaptation Physiology Group, Wageningen University, De Elst 1 6708 WD Wageningen Postbus 338, 6700 AH Wageningen, The Netherlands, email: Henk.Parmentier@wur.nl . Peter W.G. Groot Koerkamp (Prof.), Livestock Research; Farm Technology Group, Wageningen UR, email: Peter.GrootKoerkamp@wur.nl . Corresponding author: André J. A. Aarnink, P.O. Box 65, 8200 AB Lelystad, The Netherlands; phone: +31-320-293589; fax: +31-320-238094; e-mail: andre.aarnink@wur.nl . Sponsored by the Dutch Ministry of Economic affairs, Agriculture and Innovation. Abstract. This paper presents a study in which concentrations and size distributions of airborne particles were measured inside and outside typical animal houses for broilers, broiler breeder (both floor housing with litter); layers (floor housing system and aviary housing system); turkeys (floor housing with litter), pigs: fattening pigs (traditional houses, low emission houses with dry feed, and low emission houses with wet feed), piglets, sows (in individual and in group housing); cattle (cubicle house), and mink (cages). Dust concentrations in the different particle size ranges were generally higher, both in counts and mass, in poultry houses than in pig houses. The concentrations in pig houses were higher than those in cattle and mink houses. The particle counts in animal houses were highest (on average 87%) in the size ranges < 1.0 μm, while particle mass was highest in size ranges > 2.5 μm (on average 95%). Most particles outside were in the size range < 1.0 μm (99% in counts). Keywords. Particle size distribution, animal houses, dust concentration