Identification of risk factors for sub-optimal housing conditions in Australian piggeries: Part 3. Environmental...

Between autumn 1997 and autumn 1999, we measured ventilation rates (using a CO2 balance method), air temperatures, and relative humidity (using self-contained dataloggers with built-in sensors) in 160 pig housing facilities in Queensland, South Australia, Victoria, and Western Australia, in each case over a 60 h period. In some buildings, the internal air velocities above the animals were also recorded. While the monitoring instruments were being set up, a detailed questionnaire was used to collect data on major housing features and management factors. This information was statistically analyzed to quantify the effects of housing and management factors on the resulting environment conditions using a multifactorial analysis. The overall mean air temperature, relative humidity, internal air velocity, and ventilation rate were 20.3 degrees C, 58.9%, 0.12 m s(-1), and 663.9 m3 h(-1) 500 kg(-1) live weight, respectively, across all buildings. Internal building temperature and humidity were affected statistically by the type of insulation material used, the classification of buildings, and external climatic conditions. Ventilation rates were primarily affected by the type of ventilation system used, height (size) of ventilation openings, stocking density (kg m(-3)), and length, width, and height of buildings. These findings should aid the development of strategies for the industry to improve environmental control in piggery buildings.