Heat stress during livestock transport and in lairage before slaughter causes significant welfare suffering in pigs, with summer conditions creating particular risks for animals that cannot effectively thermoregulate.
Transport and pre-slaughter heat stress causes acute welfare suffering and, in severe cases, death from heat stroke before slaughter is achieved. Pigs that arrive at abattoir hyperthermic, dehydrated, and exhausted from heat exposure experience the final hours of their lives in significant distress. The welfare cost is particularly concerning because this phase represents the culmination of weeks or months of care — animal welfare that has been maintained throughout the production phase is severely compromised at the final step. Seasonal scheduling of transport to cooler parts of the day, vehicle ventilation systems, and welfare monitoring at abattoir lairage all reduce pre-slaughter welfare impairment.