By Andy Coghlan on NewScientist.com
BRAIN signals have shown that calves do appear to feel pain when slaughtered according to Jewish and Muslim religious law, strengthening the case for adapting the practices to make them more humane. "I think our work is the best evidence yet that it's painful," says Craig Johnson, who led the study at Massey University in Palmerston North, New Zealand.
Johnson summarised his results last week in London when receiving an award from the UK Humane Slaughter Association. His team also showed that if the animal is concussed through stunning, signals corresponding to pain disappear (New Zealand Veterinary Journal, vol 57, p 77).
The findings increase pressure on religious groups that practice slaughter without stunning to reconsider. "It provides further evidence, if it was needed, that slaughtering an animal without stunning it first is painful," says Christopher Wathes of the UK Farm Animal Welfare Council, which has long argued for the practice to end.
In most western countries, animals must be stunned before they are slaughtered, but there is an exemption for religious practice, most prominently Jewish shechita and Muslim dhabiha. Animal welfare groups have long argued that on welfare grounds, the exemptions should be lifted, as they have been in Norway.
Johnson's work, funded by the UK and New Zealand agriculture ministries, builds on findings in human volunteers of specific patterns of brain electrical activity when they feel pain. Recorded with electroencephalograms, the patterns were reproducible in at least eight other mammal species known to be experiencing pain.
Johnson developed a way of lightly anaesthetising animals so that although they experienced no pain, the same electrical pain signals could be reliably detected, showing they would have suffered pain if awake.
The team first cut calves' throats in a procedure matching that of Jewish and Muslim slaughter methods. They detected a pain signal lasting for up to 2 minutes after the incision. When their throats are cut, calves generally lose consciousness after 10 to 30 seconds, sometimes longer.
The researchers then showed that the pain originates from cutting throat nerves, not from the loss of blood, suggesting the severed nerves send pain signals until the time of death. Finally, they stunned animals 5 seconds after incision and showed that this makes the pain signal disappear instantly.
"It wasn't a surprise to me, but in terms of the religious community, they are adamant animals don't experience any pain, so the results might be a surprise to them," says Johnson. He praised Muslim dhabiha practitioners in New Zealand and elsewhere who have already adopted stunning prior to slaughter. They use a form of electrical stunning which animals quickly recover from if not slaughtered, proving that the stunned animal is "healthy", thereby qualifying as halal.
Spokesmen for both faiths responded by claiming that stunning itself hurts animals. Shechita UK says that the throat cut is so rapid that it serves as its own "stun". Ahmed Ghanem, a halal slaughterman based in New Zealand, says that blood doesn't drain properly from stunned animals, although this has been countered by recent research at the University of Bristol in the UK.