Transporting lambs directly from weaning to slaughter is a common practice in Chile. A long journey that includes road transport and sea-ferry crossing, lasting 48 h in total, has driven attention lately due to possible negative effects on animal welfare. The effects of weaning. followed by the long distance transport to slaughter on the concentrations of some blood constituents were studied during two commercial journeys. In each journey 500 Corriedale lambs were transported in a three-deck truck with a space allowance of 0.2 m(2)/lamb. Immediately previous to the transport the lambs were rounded up with their mothers from distant fields and weaned. In each journey 25 lambs were selected at random and a blood sample was obtained from each individual on the farm: after rounding up and weaning but before loading; after transport: once unloaded after arrival at the slaughterhouse; after 10 h lairage and 10 to 20 min thereafter, once the lambs had been driven from lairage to the stunning box and stunned, at exsanguination. The handling procedures related to rounding up and weaning, before transporting lambs for slaughter, induced high initial plasma concentrations of cortisol, packed-cell-volume, glucose, lactate and activity of creatine kinase (CK). Lactate and CK decreased after transport for 48 h immediately after, whereas cortisol increased. Transport of lambs without access to food and water for 48 h, immediately after rounding up and weaning, increased the plasma concentrations of haptoglobin and beta-hydroxybutyrate, reflecting the effects of the long-term stress and fasting. Lairage for 10 h decreased the concentrations of cortisol, glucose, CK and lactate, but not packed-cell-volume or haptoglobin; beta-hydroxybutyrate continued increasing. It was concluded that the commercial procedures of weaning and prolonged transport immediately after in lambs destined for slaughter are stressful and exhaust body reserves, and measures should be taken to improve welfare. (C) 2008 Elsevier B.V. All rights reserved.