At slaughter, cattle are stunned using a captive bolt gun. In a previous study, we simulated different bolt trajectories, using the heads of cattle of suckling breeds obtained immediately after slaughter. The aim was to determine the external landmarks on the head of cattle allowing the identification of the shooting position, which maximizes the probability of damaging the Ascending Reticulated Activating System (ARAS), and thus, the probability of inducing a state of profound and irreversible unconsciousness. To address further these questions, the present study selected in a commercial slaughterhouse, heads of cattle presenting zero, one or more indicators of risk of consciousness after captive bolt stunning. Analysis of these cattle heads shows that the probability of the presence of indicators of risk of consciousness is higher when the ARAS is macroscopically intact. The analysis also shows an association between the presence of nystagmus and breathing. Finally, the study made it possible to identify avenues for improving the positioning and orientation of shots in the slaughterhouse.
