Physiological responses of sheep during long road journeys involving ferry crossings
With a view to comparing previous findings from experimental journeys, with observations during commercial transport of sheep, hormonal and other physiological data were gathered during three long journeys (866 to 1178 km), all of which involved a sea crossing (1 h 45 min to 8 h 55 min). One was a commercial journey from the United Kingdom to continental Europe and the other two, which were simulated commercial journeys under the control of the investigators, were from a Scottish island to Cambridge. In all journeys there was a break in lairage (duration 13 to 24 h). The stocking rate on the commercial journey (0-17 m2 per sheep for shorn sheep of 35 to 37 kg body weight) was less generous than previously used in experimental journeys. In all journeys there was an apparent increase in plasma concentration of cortisol soon after loading and commencement of travel, with subsequent decline. Transient increases in beta-endorphin and prolactin were also observed but changes in creatine kinase were not obvious. Haematocrit showed slight evidence of a decline during the journeys. These findings are generally similar to those obtained in experimental journeys and there was no evidence of a hormonal response to sea conditions during the ferry crossings. When transport was resumed after a period of rest with food and water off the vehicle, the physiological responses were less marked than they had been during the first stage of the journey. Under the circumstances observed, long journeys of the type commonly practised commercially probably do not of themselves pose a major welfare challenge.