Effect of lairage during 24 h of transport on the behavioural and physiological responses of sheep

Suffolk × Greyface lambs, 16 weeks of age, weighing 30-40 kg, were transported by road, confined on a stationary vehicle or received no treatment (controls). The effects of 24 h continuous transport or confinement were compared with those of 12 h treatment followed by 12 h lairage, 3 h lairage or 3 h access to feed and water without unloading, followed by another 12 h transport or confinement. After 3 h of treatment, plasma cortisol concentration was higher in transported sheep than in confined sheep and controls (P<0.05) and after 24 h transport cortisol concentration was still higher that of controls. There was an increase in plasma free fatty acids after 12 h and β-hydroxybutyrate after 24 h in transported sheep. There was no biochemical evidence of dehydration during the journey, although sheep transported for 24 h had a greater water intake after transport than controls. Sheep given hay and water on the vehicle had a lower water intake than sheep in lairage and a greater water intake after transport than any other group. Plasma cortisol concentration was higher during the 2nd part of the journey in sheep that were given hay and water but not unloaded than in lairaged sheep. There was no difference between lairage treatments in the time spent lying down during the first and second 12-h treatment period. There were fewer potentially traumatic events (falls, loss of balance, butting etc.) during the second 12 h of transport than during the first 12 h with no difference between lairage treatments.