Examining physical methods for on-farm killing of turkeys
Despite routine on-farm killing of turkeys, there had been no scientific investigation into the effectiveness of on-farm killing methods. The objectives of this research were (1) to compare the effectiveness of a non-penetrating captive bolt (Zephyr) with blunt trauma and manual and mechanical cervical dislocation using brainstem reflexes as indicators of insensibility, and (2) to examine brain damage resulting from each killing method. The Zephyr was comparable to blunt trauma. Both methods consistently resulted in immediate insensibility leading to death, as indicated by the sustained absence of eye reflexes and breathing. Conversely, neither method of cervical dislocation resulted in rapid insensibility. Cervical dislocation produced subdural haemorrhage, but minimal microscopic brain trauma, whereas the Zephyr and blunt trauma resulted in macroscopic subdural haemorrhage and microscopic haemorrhage in all turkeys that were rendered immediately and irreversibly insensible. The Zephyr and blunt trauma appear to be effective for humane on-farm killing of turkeys.