Effects of Handling Procedures and Transport Vehicle Design on the Welfare and Meat Quality of Pigs
The objectives of this project were to study stressors experienced by market pigs during handling and transport, to identify components of these stressors that can be modified, and to assess whether modifying these components can reduce stress and/or improve the ability of pigs to recover. This researched showed that the use of double deck hydraulic trailers resulted in less stress and better meat quality compared to pot belly trailers, likely due to the absence of internal ramps and reduced handling stress at loading and unloading. In addition, pigs spent more time standing during transport in winter, likely to conserve heat by minimizing contact with the trailer floor. Heart rate and internal body temperatures were also higher in winter, suggesting increased metabolic rate. In eastern studies, hot summer temperatures and shorter transport times resulted in increased stress on pigs and higher levels of PSE meat traits, while in western studies, long transport times in winter resulted in greater stress compared to summer conditions. Indeed, it was shown that pigs transported long distances in winter showed increased drinking in lairage, indicating dehydration and produced more hams with RSE and DFD meat characteristics. Lastly, there is significant variation in temperature and humidity conditions between compartments on all trailers studied, with upper rearward compartments having lower temperatures and central front compartments being warmer. Results of this research have implications for industry, regulators and for future research to improve transport conditions.