Defra - Department for Environment, Food and Rural Affairs.

Science Search

Science and Research Projects

Return to Science Search homepage   Return to Project List

Stunning tongs and stunning tong electrode development - MH0111

Traditional designs of electrical stunning tong electrodes were moderately smooth, serrated edged, circular electrodes, containing saline soaked sponges produced for the application of relatively low voltages. Current transfer was maintained through the large, wet contact reducing the otherwise high electrode/skin impedance to a minimum and thus maintaining the optimum current flow with a given, low voltage. More recently, researchers have demonstrated that the minimum current levels required for effective elecreical stunning of pigs are higher than that obtainable with low voltage systems (1 & 2). Modern tong design, for use with high voltage systems has evolved electrodes with sharp, teeth-like contacts that would in most circimstances petnetrate the skin. Very little research and development has been carried out into the materials, design and constrictuion of tong electrodes to allow the optimum transfer of current to the animal. The electrode applicaton is generally via hand-held tongs to the head of the animal spanning the brain. Concerns has been experssed by animal welfarists over the design of the `modern` tongs and electrodes particularly when the current is misapplied. Tongs are more often fabricated from stainless steel and are thus very heavy for repetitive use and are often difficult to apply in the confines of a restrainer or stunning pen due to their shape. They are often designed to be universally applicable to pigs, sheep and calves when the shape of the application site varies from specied to species. The main objective is to investigate the materials, design and constrcution of an optimum tong electrode for electrically stunning pigs, sheep and calves and to design and develop tong design to improve current application.
Project Documents
• Final Report : Stunning tongs and stunning tong electrode development   (117k)
Time-Scale and Cost
From: 1997

To: 2002

Cost: £189,210
Contractor / Funded Organisations
University - Bristol
Animal Welfare              
Plants and Animals              
Fields of Study
Animal Welfare