ByMarcus Dysch, Marcus Dysch
Campaigners have rejected scientific tests which claimed to undermine one of the key justifications for the religious slaughter of animals.
Shechita UK said the findings had "no meaningful impact on the debate" about the production of kosher meat.
The tests were carried out by academic psychiatrist Colin Brewer and Dr Peter Osin, a consultant pathologist at the Royal Marsden Hospital in London.
They compared beef and venison which had been shot to pieces of halal and kosher beef.
The scientists claimed there was no significant difference in blood loss whether or not animals were pre-stunned.
Jews and Muslims are forbidden to consume blood.
Under the shechita process animals are not stunned before slaughter, a practice animal rights campaigners oppose.
In a letter to Dr Osin, Shimon Cohen, the director of Shechita UK, said that the level of blood loss was not a relevant factor.
"The Jewish community has never contended that there is less blood in a carcass following shechita than following conventional mechanical slaughter.
"Shechita is practised because it is religiously mandated as the only method by which Jews may obtain kosher meat and poultry for food. It is both humane and highly efficient."
Mr Cohen said Dr Osin's findings "appeared to be based on very limited material, without information about sampling".
The All-Party Parliamentary Group on Beef and Lamb published a report into religious slaughter last month and said more research was needed on the practices.
Activists have repeatedly lobbied against kosher and halal slaughter. In March, pro-shechita campaigners rejected comments made by the leader of the country's vets, John Blackwell, who suggested religious slaughter should be banned in Britain.