The influence weather station location on feedlot microclimate monitoring and its impact on heat load monitoring in Australian feedlots

Globally, feedlots rely on weather data to provide foundational information describing and predicting cattle exposure to heat load throughout the summer months. Anecdotally, in Australia feedlots are installing weather stations in close proximity to office buildings, for ease of maintenance. However, there is limited information available describing the variability of microclimatic conditions within feedlots, nor do recommendations exist regarding the ideal placement of weather stations to provide an accurate representation of the thermal environment experienced by feedlot cattle. The aim of this study was to evaluate the variability between in pen microclimate obtained from within pen data loggers, and weather stations situated at feedlot pens and in close proximity to the feedlot office. A total of six (n = 6) Australian feedlots covering a broad geographical range were enrolled into this study. Each feedlot had an automated weather station located in close proximity to i) office buildings (50–75 m from office) and second station located at ii) feedlot pens (2–10 m from pens). In addition (n = 16) ambient temperature (T A , °C) and relative humidity (RH, %) data loggers were placed within a number of pens at each feedlot. From these data comparisons between within pen, at pen and office climatic conditions were evaluated. The relationships between the climatic variables on the two weather stations located at each feedlot were determined using regression analysis, where linear and quadratic relationships were evaluated. Results from this study provides evidence highlighting the variability of within feedlot microclimate conditions, emphasising the importance of onsite weather monitoring. Weather station placement at feedlots is important to ensure that the data collected provides an accurate representation of the feedlot climate conditions. This study highlights the importance of identifying the ideal location for correct weather stations placement for feedlots. Failing to position onsite weather stations in an appropriate location may result in an under- or over-estimation of heat load that cattle are experiencing, which likely reduces the effectiveness of heat load mitigation strategies utilised. • Considerable microclimate variability exists across feedlot sites. • Weather station placement is critical to providing accurate representation of cattle comfort. • Determining within pen microclimates will facilitate better understanding of heat load on cattle. • A combined approach using on-site conditions and cattle behavior is essential for heat load management.