Orford, F., Ford, E. A., Brown, S. N. et al. 2016. The evaluation of two commercial electric sheep stunning systems: current applied and the effect on heart function. Animal Welfare 25(3), 331-337.

The maintenance of head-only minimum stunning currents for sheep to ≥ 1.0 Amp as per current legislation was examined in two trials in a commercial abattoir. In the first trial, a Jetco MS100 stunner failed to maintain the current to > 1.0 Amp in 118 of the 228 sheep. In a second trial, a Jetco MS105 delivered sufficient current in all sheep (n = 275) to meet the legislative requirement, apart from a single animal. Recorded electrocardiograms showed a regular heartbeat, with no evidence of ventricular fibrillation, in all animals in both trials following stunning and neck-cut. Only one of the two stun units may therefore be considered to meet the statutory requirements but both may meet the requirements for halal slaughter where pre-stun is considered acceptable.