Constant current stunning effects on bird welfare and carcass quality

The effectiveness of electrical stunning of broiler chickens, applied using a constant current control device, was assessed in terms of both the retur n of breathing and neck resistance and subsequent carcass quality. Effectiv eness of stunning was assessed by stunning individual birds with 105 mA/bir d using 50, 500, or 1500 Hz sinusoidal AC for 1 or 4 sec. Carcass quality w as assessed using the same device in two semi-commercial trials where stunn ing was applied using 50, 500, or 1500 Hz sinusoidal AC at four preset curr ent levels, 80, 105, 120, and 150 mA/bird, in a constant current multibird waterbath. The duration of lack of neck resistance produced by the stun, wh ere ventricular fibrillation was not induced, was similar regardless of the waveform-frequency combination employed. Stunning current level had no eff ect on the incidence of hemorrhagic conditions in the processed carcasses. High frequency waveforms were associated with a significant reduction in th e incidence of breast muscle hemorrhaging, which indicates that their use c ould have a considerable commercial advantage.