Look, but don’t touch: indicators of unconsciousness in stunned livestock
When it comes to electrically stunned animals, processors can observe a variety of indicators to determine unconsciousness but should avoid using the corneal reflex.
The corneal reflex has been one of the go-to indicators of unconsciousness in stunned livestock for decades. The ease of the procedure (a quick touch of the eye) and the seemingly discrete outcome (a blink) make it an ideal assessment tool, at least on the surface.
For animals that are mechanically stunned or euthanized with a captive bolt gun or firearm of appropriate caliber, corneal reflex appears to be a reliable assessment tool. However, the use of the corneal reflex is no longer recommended for electrically stunned animals because close observation has revealed that corneal reflexes may occur in animals with no other signs of life. Other indicators of unconsciousness should be used for electrically stunned animals as researchers work to understand why the corneal reflex occurs in electrically stunned animals.