Tissue resistivities and current pathways and their importance in pre-slaughter stunning of chickens

The failure of commercial pre-slaughter electrical stunning to stun effectively all birds may be, in part, a result of the current following slightly different paths through the tissues of different birds. Resistivity can be used to predict current pathways, and methods are presented for determining the resistivity of a tissue in freshly-killed or anaesthetized adult fowls. A variety of tissues were tested including comb, skeletal muscle, epithelium, brain, skull bone, heart and liver. The resistivity of a particular tissue varied little between birds, with the exception of skull bone in which resistivity differed markedly from bird to bird. This variation in skull bone resistivity may explain why some birds are inadequately stunned, since in these individuals the current density in the brain is likely to be insufficient to induce an adequate epileptic seizure.