During transportation to an abattoir, pigs can be exposed to a variety of different stressors, eg temperature change, noise and sudden movements (acceleration, braking, cornering) (Lambooij & van Putten 1993). Vibration and unfamiliar movements of the vehicle might elicit a stress response (Dantzer & Mormède 1983; Geers et al 1994). The cardiovascular system is influenced by vibration, resulting in increased heart rate and blood pressure, and peripheral vasoconstriction (Randall et al 1995a). The stress caused by transport may adversely affect animal welfare and cause economic losses related to mortality, carcass damage, and decreased meat quality (Tarrant 1989; Warriss et al 1994). The motion of the floor surface in a transporter is dependent upon the vehicle’s suspension, load, floor rigidity, engine speed, transmission, road speed, road surface, wheel imbalance, etc. Aspects such as acceleration, braking, and cornering, which are under the control of the driver, affect an animal’s ability to maintain postural stability (Randall 1992; Randall et al 1995b). Since 1990 French drivers transporting pigs have undergone education (two-day sessions organised by ITP, Institut Technique de Porc, Paris, France) to help stress that good handling practices are important, not only from an economic point of view, but also in terms of public perception, ie the image consumers have of pig production. After these training sessions started, many slaughterhouses recorded decreased levels of skin damage (Chevillon 1998). The aim of this study was to investigate the possibility of reducing transported pigs’ stress levels by adjusting the driving style of different drivers. To this end, the effect of driver and driving style on pigs’ stress parameters such as behaviour, salivary cortisol concentrations, and heart rate variability was explored during a short journey. Additionally, the effect of different types of trailer acceleration (longitudinal, lateral, and vertical) on these variables was investigated. One hundred and thirty-five cross-bred pigs (Pietrain × Hypor) were transported in groups of five on a trailer towed by a jeep. Three different drivers transported the pigs using a normal, a quiet, and a wild driving style (the latter two in relation to their normal style). Driving style mainly had an effect on the longitudinal and lateral accelerations. Salivary cortisol increases were lowest for the wild driving style. The latter can be explained by the shorter duration of these journeys and not by the accelerations, thus it is our view that acceleration due to manoeuvring as opposed to acceleration due to overall speed should be avoided. Also, in practice, journeys should take as brief a time as possible. Increasing acceleration saw an increase in the proportion of pigs standing during the journey and a decrease in the proportion of pigs lying down. Measurements of variability in heart rate revealed that lateral acceleration was an important stressor for pigs. We concluded that, as driving style has an effect on different stress variables, increased driver awareness of the effects of their driving on the responses of pigs, would improve pig welfare.

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