New Zealand is well advanced in slaughter practices in all meat works, where cattle, sheep, goats and pigs are electrically stunned before their throats are cut severing the carotid arteries. The interval between stunning and sticking (bleeding) is well within the requirement of overseas markets, and research is constantly advancing technology to shorten this interval and prevent animal suffering at slaughter.
The concern now is for sheep that are slaughtered on farms for home consumption and for dog tucker. These sheep simply have their throats cut and then their necks broken severing the spinal cord. Skilled operators do both these actions with the one blow of the knife and a twist of the head around the left leg.
In the past we have assumed that cutting a sheep's throat and simultaneously breaking its neck produced complete insensibility to pain. But recent investigation by the late Professor David Blackmore, has shown that our long-held assumption to be wrong.
Research on sheep has show that the brain may react to pain after the throat has been cut, and until the animal becomes unconscious through lack of oxygen. And whether the neck is broken and the spinal cord severed makes no difference. Professor Blackmore believed that attempting to sever the spinal cord could easily add to the pain felt by the animal before it dies.
So the main question for shepherds killing sheep for the house or the dogs is how to kill sheep humanely, after 150 years of cutting their throats!
A properly positioned captive bolt pistol will dispatch animals in a humane manner but few farmers have these. An effective shot with .22 rifle will do the job correctly, but care must be taken to prevent stray bullets ricocheting. It's very important to know the correct position on the animal's head to aim the shot. If you are not sure, then check with your veterinarian.
A Code of Welfare on the slaughtering of stock at approved premises contains useful diagrams to show the correct position to shoot an animal. This is Code number 10 and is available from MAF, Box 2526 in Wellington.
If you cannot shoot a sheep, then it should be stunned by a blow on the correct position above the brain with a heavy blunt instrument. Then the animal's throat should be cut immediately to prevent any possibility that it may recover consciousness.