ARS | Publication request: Electrical Stunning Systems

Submitted to: U.S. Poultry and Egg
Publication Type: Proceedings
Publication Acceptance Date: July 31, 2006
Publication Date: August 9, 2006
Citation: Buhr, R.J. 2006. Electrical Stunning Systems. In: Proceedings of the Poultry Handling and Care Workshop. United States Poultry and Egg, August 9-10,2006. 2006 CDROM.

Technical Abstract: This presentation is an overview of the mechanics of electrical stunning of broilers and the physiology associated with stunning, bleeding, and the rapid progression to death. Stunning and bleeding compose a relative short time period in the 6-week life of a commercial broiler, about 2.5 to 3 minutes. Electrical stunning of commercial poultry was common by 1943 and the Humane Slaughter Act of 1978 required that stunning of broilers result in the insensibility to pain prior to bleeding and the cessation of all ventilatory movement prior to scalding. It is important to remember that electrical stunning by itself renders the broiler unconscious and unable to perceive pain stimuli but all stunned broilers should recover consciousness in the absence of bleeding. It is therefore important that stunning and bleeding be considered integral steps in a single process as opposed to independent operations. In contrast electrocution results in death in the complete absence of bleeding by inducing cardiac failure. Involuntary movements during bleeding may be confused with ventilatory movements or progression to regain consciousness. Both ventilatory movements and consciousness require a functional brain. Decapitation is considered by the AVMA as a humane method for euthanasia and it has been shown when decapitation follows electrical stunning ventilatory movements during bleeding are eliminated prior to scalding. Decapitation results in an instantaneous death, and eliminates all possibility of regaining consciousness or the ability to perceive pain. Broiler carcasses subjected to electrical stunning followed by decapitation resulted in no differences in bleed-out blood loss, respiratory tract bacterial recovery, defeathering ability, carcass quality related to broken bones and hemorrhages, or meat quality related to pH, color, yield and tenderness shear. The implementation of decapitation of stunned broilers is becoming a more common practice in commercial broiler processing plants throughout the United States.