Studies on the return of physical reflexes in pigs following electrical stunning

In order to obtain quantitative information on the duration of insensibility in pigs (60-80 kg) following electrical stunning, experiments were carried out using 50 Hz alternating current for 3 and 7 s current durations at different voltages. The following features were examined: the mean current received by each pig, the period of loss of reflexes and the time to return of spontaneous activity, and cranial nerve reflexes. In particular the return of breathing was used as a first sign of recovery, and the response to a nose prick and presence of the righting reflex were used as indicators of overt consciousness. A minimum current in excess of 406 mA was required to effectively stun these pigs with sufficient duration of loss of reflexes. At least 150 V for 3 s current duration should be used and a maximum stunning to exsanguination interval of 15 s is considered sufficient to ensure pigs of this size do not regain consciousness following the stun.