[Some features of electrical and mechanical stunning in ruminants]

The present studies are concerned with methods of mechanical and electrical stunning as used in ruminants. The object is to acquire a scientific basis for the correct use of these procedures in slaughter-houses. In all experiments studies on living animals, cerebral activity (electro-encephalogram) was measured using electrodes which had been surgically implanted the previous day. When animals are stunned by concussion, unconsciousness is not induced in every case. When a slaughtering mask was frontally or occipitally applied to the head, unconsciousness was produced. To effectively induce unconsciousness, the bolt of the captive bolt pistol should carry sufficient energy to damage the cerebral cortex and the deeper portions of the brain directly or by shock waves following penetration of the cranium. The forces which may be developed by the variously coloured cartridges of the brands of captive bolt pistol differ markedly. Regulations regarding the relationship between the colour of the cartridge and the potential forces would appear to be essential.