After transport to the slaughter plant, pigs may be kept in lairage for up to 24h before being killed. This facilitates smooth, continuous operation of the slaughterline and, it is commonly believed, allows the animals to rest and so recover from the stress of transport. We have tested this latter belief by examining indices of stress in blood collected at slaughter from pigs kept in lairage for various times.
A total of 320 LW x (LW x LR) pigs (89 kg) of both sexes were used. They were killed in ten batches. Prior to slaughter they were transported for 2h (80 km) at a stocking density of 0.52 m2 per 100 kg live weight. On arrival at the IFR-Bristol slaughterhouse the pigs were killed either as soon as practicable after unloading off the transporter (Oh lairage), after 3h in lairage or after holding in lairage overnight (21h). Half the pigs held overnight were fed in lairage (in the late afternoon), half were not. At slaughter therefore, pigs in the four different lairage treatment groups had been subjected to food withdrawal periods of 3, 6, 16 and 24h.