Hormonal and physiological effects of a 15 hour road journey in sheep: comparison with the responses to loading, handling and penning in the absence of transport.

A controlled study was carried out to investigate the physiological effects of road transport on sheep. Animals (n = 10; body weight 38.9 +/- 1.3 kg), previously with catheters in their jugular veins, were rounded up and loaded onto a vehicle where they were held in a communal pen with eight other lambs. Blood samples were taken at 30 min intervals during the next 15 h while the vehicle remained stationary or was driven a distance of 548 miles (876 km). Measurements were made of plasma concentrations of cortisol, prolactin, creatine phosphokinase and lactase dehydrogenase isozymes and also of plasma osmolality, haematocrit and body weight; heart rate was also recorded in one animal. Loading and the start of driving produced large increases in cortisol and prolactin concentrations. Heart rate also increased whereas osmolality and haematocrit decreased. The major changes in hormone release occurred in the first 3 h period while, during the remaining 12 h, the stimulatory effect of transport was present but small. Body weight loss was similar under both stationary and driven conditions.