Animals are dying in unnecessary agony because of a lack of understanding over how stunning stops them feeling pain when their throats are cut, research shows.

In conventional slaughterhouses, cows, sheep and chicken are stunned, usually with an electric shock, to ensure they are unconscious before their throats are cut.

This minimises suffering but in a number of Muslim abattoirs the animals are not stunned over fears it is not permissible, or 'halal'.

In a number of Muslim abattoirs animals are not stunned before slaughter over fears it is not permissible, or 'halal' but research suggests this is due to ignorance of the process (file image)

A study by researchers at the University of Bristol suggests some Islamic scholars are ignorant about the humaneness of stunning, leading to animals dying in pain,The Times reported.

Widespread research shows the welfare benefits of pre-slaughter stunning. The electric shocks lessen the pain felt by animals when their throats are cut.

A number of industry bodies have spoken out against the slaughtering of animals without pre-stunning, with the British Veterinary Association saying there is an 'unacceptable time lapse between slaughter and the onset of permanent insensibility [loss of feeling] when animals are not stunned'.

Animals must also be stunned before slaughter under EU regulations.

However Britain allows an exemption for those who oppose because of religious beliefs and the number of animals killed without stunning appears to be on the rise.

RITUAL KILLING OF ANIMALS FOR RELIGIOUS REASONS HALAL Halal slaughtering involves cutting through the large arteries in the neck with one swipe of a blade, while a Muslim butcher recites a religious verse. All blood is then drained away since the consumption of blood is forbidden under Islamic law. Under Islamic law, an animal must be slaughtered by having its throat cut while it is conscious. KOSHER According to the laws, in order for a meat to kosher it must come from an animal that meets the kosher rules. These are the animal must be ruminant and have split hooves. Ruminant animals chew food once and swallow, before regurgitating it and chewing again. Animals that Jews can eat include cows, sheep, goats and deer. They cannot eat pigs despite the fact it has split hooves because it is not a ruminant animal. Before slaughtering, the animal must be healthy and uninjured and a sharp knife is used to slice through the main arteries and windpipe, causing a drop in blood pressure that causes the animal to lose consciousness. Jews believe this is a way of killing that shows 'respect and compassion' as set out in Jewish law.

Some 2.4 million sheep and goats were put to death using the religious method in halal and kosher abattoirs in 2013 – a rise of 60 per cent on 2011.

According to analysis by the Food Standards Agency, some 37 per cent of sheep and goats, 25 per cent of cattle and 16 per cent of poultry were killed in this way in halal premises.

Researchers from the University of Bristol School of Veterinary Science questioned Islamic scholars and Halal consumers on the use of pre-slaughter stunning.

The study is published in the journal Meat Science.

Some 69 per cent of scholars said they did not agree that stunning prior to slaughter had been showed to reduce the pain felt by animals, according to The Times.

However more than 95 per cent of the scholars and 53 per cent of consumers agreed that if stunning did not result in death, cause physical injury or obstruct bleed-out, the meat would be considered Halal.

The study said: ' The lack of understanding of stunning among some scholars has resulted in the issuance of confusing fatwas on the suitability of stunned meat for consumption by Muslims.

'There is an urgent need for these scholars to be given theoretical and practical education on stunning and other modern slaughter techniques such as mechanical slaughter.

'This will help them make informed decisions about the suitability of these techniques for Halal production.'

Gudrun Ravetz, president of the British Veterinary Association said: 'Our view is that all animals should be stunned before slaughter, based on peer reviewed evidence that indicates an unacceptable time lapse between slaughter and the onset of permanent insensibility when animals are not stunned.

Britain allows an exemption for those who oppose because of religious beliefs and the number of animals killed without stunning appears to be on the rise. File image

'A number of notable bodies including the Farm Animal Welfare Committee and the EU Food Safety Authority all agree that there is a high probability that the cutting of sensitive tissues at the neck will trigger a significant pain response in a conscious animal.

'Given the barrage of evidence about the humaneness of stunning before slaughter the veterinary profession is persuaded that animals must be stunned.