Experimental study on temperature difference between the interior and exterior of the vehicle transporting weaner pigs

Transporting pigs poses a significant challenge in maintaining proper interior thermal conditions. This study conducted 36 field trials run in Denmark and collected data from a certified livestock vehicle, during journeys of 8 h and 23 h respectively. This study aims to investigate the air temperature inside a livestock vehicle during the transportation and the influence of five factors on DT (difference in air temperature between interior of the vehicle and exterior): compartment location, deck height, height of openings for natural ventilation, wind speed and vehicle speed. The compartment location was the most important influencing factor of interior air temperature. The maximum percentage of time when air temperature exceeded 30 °C was 13.6% observed in the front compartment of trailer. The maximum difference in mean DT between the front and rear compartments at the same deck was 11.0 ± 0.67 °C occurred in the lorry. The maximum differences in mean DT between the two investigated deck heights were 1.2 ± 0.39 °C in the lorry (70 vs. 90 cm) and 0.9 ± 0.26 °C in the trailer (60 vs. 80 cm), respectively. The DT decreased with increasing height of opening for natural ventilation and wind speed, while the DT was insensitive to vehicle speed. Extra sensors installed on the front partition wall during the last 4 journeys showed significant temperature variability (up to 12 °C) within compartment. Further studies identifying the efficient monitoring of thermal condition and prompt interior environmental control are needed in vehicles for pig transport.