Determinants of endotoxin levels inside pig confinement buildings: Pilot study findings and recommendations for further research

Abstract

There is a growing concern about the emission of endotoxins by farms into the surrounding environment. Endotoxins have been linked to respiratory disease in both humans and pigs. Endotoxin levels in stables may exceed 1000 EU/m3 in a majority of pig farms. This pilot case-control study aims to determine the endotoxin levels inside pig confinement buildings and determine if there is are any associations between these levels, herd respiratory health and potential exposure determinants, such as ventilation and other farm management characteristics, as well as associations between herd respiratory health and stable management characteristics. Thirteen pig confinement rooms housing weaners aged 33 to 66 days were visited once during May and June 2018. Determinants were inventoried and an electrostatic dust collector (EDC) was left in the room for two weeks. High levels of endotoxins were found (GM 1016 x 104 EU/m2). No significant association was found between endotoxin l evels and farmers or veterinarians reporting a history of herd respiratory health problems (p = 0.22). Associations were found between a reported history of respiratory disease and building age (OR = 0.760; p = 0.045) and plastic slatted floors (OR = 30; p = 0.027). Feed protein content may be a possible determinant for endotoxin level (b1 = 0.025; p = 0.053). We make recommendations for future research in this area, most importantly improving the generalizability of the sample population and investigating the spatial aspects of endotoxin detection using EDC’s.