Effect of stunning on spontaneous physical activity and evoked activity in the brain.

1. The effect of stunning current on the time to recovery of physical activity, and on somatosensory evoked potentials (SEPs) in the brain, was examined in broiler chickens. 2. Increasing stunning current was associated with an increase in the time to recovery of tension in the neck muscles and with an increase in the incidence of loss of SEPs. 3. Currents greater than 105 mA per bird provided 52 s or more of apparent insensibility; currents greater than 120 mA were associated with absence of SEPs following the stun.