Some neural and behavioural aspects of electrical and mechanical stunning in ostriches

Different electrical and mechanical stunning procedures were studied in ostriches to determine the effectiveness of the method. Fifty-eight South-African Black ostriches were equipped with EEG electrodes and stunned with three different electrical head-only methods and with a new captive needle pistol, using air pressure. The first stunning procedure consists of two trials. In the first trial a total of 45 ostriches were stunned with a voltage of 200 V (spiked electrodes) during 1 s. Unfortunately, in 10 animals the electrodes were disconnected. A general epileptiform insult on the EEG followed by recovery was observed in 20 ostriches. Another eight animals died after recovery and five showed an iso-electric line and were dead. The total duration of the insult was 25±10 s. The measured current was 463±120 mA. In the second trial a constant current of 400 mA was administered to 13 ostriches. In one animal the electrodes were disconnected. Eight out of 12 animals showed a general epileptiform insult, two of them showed an iso-electric line and two did not show the characteristics of a general epileptiform insult. The total duration of the insult on the EEG was 21±8 s. The measured current was 365±91 mA and the voltage 191±27 V. During the second stunning procedure four and seven ostriches were stunned with 200 V (spiked electrodes) and 48 V (blunt electrodes), respectively, during approx. 6 s. They all died. In addition, a group of 20 ostriches stunned with captive needle pistol using air pressure showed unconsciousness after stunning by the appearance of theta and delta waves tending to an iso-electric line on the EEG trace. It is recommended to use at least 500 mA to stun ostriches effectively and to use a short stun-stick interval or to kill them by a long stunning duration. The captive needle pistol, using air pressure, can be an alternative for electrical head-only stunning.