Transporting pigs to slaughter is a major source of welfare harm — from mixing unfamiliar animals to temperature extremes and journey durations that cause exhaustion, injury, and death.
Pig transport welfare involves a cascade of stressors that compounds from loading to slaughter. Mixing unfamiliar pigs at loading triggers aggressive encounters. Novel environments, vehicle motion, noise, and vibration cause fear responses. Temperature extremes — heat in summer, cold in winter — cause physiological stress and mortality. Prolonged journeys without water cause dehydration. At the destination, lairage conditions and CO2 stunning (which causes distress before unconsciousness) add further welfare harms. Research shows that stunning alternatives (electrical head-only stunning) produce faster and less aversive unconsciousness for pigs, but CO2 systems are widely adopted for operational efficiency. Minimizing journey time, maintaining appropriate social groups during transport, and improving stunning methods are the key welfare intervention points.