CO Stunning in Pigs: Physiological Deviations at Onset of Excitatory Behaviour.

Stunning by carbon dioxide (CO) inhalation is controversial because it is associated with vigorous movements and behaviours which may or may not be conscious reactions. Furthermore, it is unknown whether some behaviours might indicate the transition into unconsciousness. Our study objective was to investigate the loss of consciousness during CO stunning by linking physiological variables (in particular pH, PaO and PaCO) to the onset of observed behaviours.