A leading vet has spoken out against the "unacceptable" rise in the number of farm animals slaughtered by having their throats cut while fully conscious.
The practice is allowed under UK and EU law to satisfy the dietary requirements of Jews and Muslims.
However, there is evidence that far more animals are being killed this way than is necessary for religious reasons alone, according to Professor Bill Reilly, a past-president of the British Veterinary Association (BVA).
Writing in the Veterinary Record, he calls for action to curb, if not halt, the slaughter of animals for meat consumption without prior stunning. He also suggests that some abattoirs might be refusing to stun animals before slaughter simply to cut costs.
Although legislation permits Schecita (Jewish) or Halal (Muslim) "non-stun" slaughter, it states that this must not cause "unnecessary suffering".
But Prof Reilly insists the animals suffer a great deal. As a postgraduate veterinary student in the 1970s he was "appalled" to witness Schecita slaughter for the first time. "The distress, fear and pain were there for all to see (and hear) in the abattoir," he wrote.
The former Farm Animal Welfare Council (FAWC) had concluded that throat-cutting resulted in "very significant pain and distress", said Prof Reilly.
A report from the EU-funded Dialrel Project, which promotes international dialogue on issues of religious slaughter, came to a similar view based on the fact that the throat was rich in nerve endings.
Prof Reilly wanted to see wider adoption of the "three Rs" (Replace, Reduce and Refine) principle applied to the use of animals in medical research. This would mean conducting an on-going dialogue to persuade religious communities that stunning animals before slaughter actually does comply with their religious texts.
A spokesman for the Food Standards Agency (FSA) said the results of their survey on animal welfare in slaughterhouses indicated that the number of animals not stunned prior to slaughter is "relatively low", and accounted for 3% of cattle, 10% of sheep and goats, and 4% of poultry.