Many reports have examined the effect of subjecting animals to stress and a variety of physiological indices have been used to monitor their responses. The indices are often only measured at one point in time and compared to resting levels. Problems could arise in interpretation of the results especially where there is little or no information on the time course of response. This work examined the pattern or response of various indices to the stress of negotiating a loading ramp.

Four pigs of approximately 60 kg live weight were surgically prepared and indwelling catheters placed in both jugular veins. The animals were allowed to recover for three days and to become accustomed to the blood sampling procedure before the experiment. The pigs were driven individually up a 2.44m long ramp which was set at an angle of 34° lo the horizontal, the maximum allowed under UK legislation for internal vehicle ramps (Transport of Animals (Road and Rail) Order, 1975). Nine blood samples were removed at intervals from each pig. The whole process was repealed on each individual pig for three days.