In 2016, there were 278 licensed slaughterhouses in Britain. Animal welfare organisations are rarely permitted to visit slaughterhouses however Viva! has been able to obtain video footage of stunning and killing. We have also reviewed scientific research on slaughter. As a result, we have built up an extremely disturbing picture of the reality of Britain's killing factories.

How many animals are killed?

Over a billion farmed animals in Britain are killed each year in slaughterhouses.

This include over 10 million pigs, over 15 million sheep, 14 million turkeys, 15 million ducks and geese, 982 million broiler chickens, 50 million boiling fowl (including so-called 'spent' hens) and over 2.6 million cattle. Add to that 4.5 billion fish and 2.6 billion shellfish you have a total of over 8 billion animals killed in the UK each year.

Legislation and enforcement

Legislation in slaughterhouses is covered by The Welfare of Animals at the Time of Killing (WaToK) regulations.

The Food Standards Agency (FSA) is responsible for ensuring that legislation is being enforced in UK abattoirs. Official veterinary surgeons (OVSs) monitor hygiene and welfare standards with meat hygiene inspectors. The FSA has been criticised by the European Commission for not having enough OVSs in both poultry and red meat abattoirs. OVSs are only obliged to observe slaughter once a day and Viva! fears that inspectors spend most of their time monitoring hygiene procedures once animals have been killed, rather than observing stunning and slaughter.

Slaughtermen

The Scientific Veterinary Committee of the European Commission says that personnel involved in handling, stunning and slaughtering animals should be trained on a periodical basis. This advice has been ignored.

Viva! has discovered that slaughterhouses are still paying their staff according to the number of animals killed in a day. The Farm Animal Welfare Council says that this practice is not in the interests of the individual animal. Slaughtermen may not want to point out problems under this payment system and there is a risk that enforcement officers could be intimidated or harassed by workers if they need to stop the line. Defra and the Meat Hygiene Service say that it is not their business how slaughterhouses choose to pay their workers.

Stun to kill techniques

Slaughter in the UK is still predominantly based around the notion that the heart must continue beating after an animal's throat has been cut in order to pump out the blood. Studies have shown that in fact, it makes no difference whether an animal's heart is still beating - the amount of blood lost will be the same. As a result, new techniques have been developed which stun and kill animals at the same time - either by using gas (used for birds and pigs) or by using electricity to cause unconsciousness and simultaneously give the animal a cardiac arrest (used for sheep, pigs and cattle. See also Chickens, Turkeys, Ducks and Geese). Only a small percentage of abattoirs currently use these techniques.

These methods do at least remove the risk of animals regaining consciousness while they are bleeding to death. However, gas mixtures do not kill instantly and can cause great distress if they contain carbon dioxide. The Scientific Veterinary Committee of the EU say that when electricity is used , animals do not always lose consciousness and can therefore suffer a 'potentially painful' cardiac arrest.

Cattle slaughter

The majority of cattle are stunned with the captive bolt pistol. Penetrative captive bolt stunners drive a bolt into the skull and cause unconsciousness both through physical brain damage and the concussive blow to the skull. The bolt on a non-penetrative stunner is 'mushroom-headed' and impacts on the brain without entering the skull. Unconsciousness is caused by the concussive blow.

If an animal is not accurately stunned or the correct cartridge strength is not used, the stun will not be effective. These animals experience the pain of being shot in the head and will either be stunned again (a difficult procedure) or continue on for knifing whilst conscious.

In an attempt to improve accuracy, legislation requires that cattle are either confined in a stunning pen or have their heads 'securely fastened'. However, head restraint systems can cause great distress. The MHS says that 17% of abattoirs either do not use a restraint or use an "inefficient" restraint which can result in the stun being delivered ineffectively.

Says abattoir vet Gabriele Meurer, 'Not many animals stand still. They are all upset, some very frightened and some move violently. The animals are never given time to calm down. Sometimes the slaughterman misses, wounding the animal terribly instead of stunning it. It may happen that the second shot cannot be done immediately and the animal is suffering for quite some time.'

In addition to the stress of being in an unfamiliar environment, the electric goad can legally be used on the hindquarters of cattle and pigs if they are refusing to move forwards. This cruel device is intentionally designed to cause pain.

Worn out dairy cows may be subjected to a painful experience before they are killed. It is becoming increasingly common for novice artificial inseminators to 'practise' on cull cows in abattoirs. For welfare reasons, novice inseminators are advised to practise only on cows who will be slaughtered on that day. The message here is that this practice is considered distressing for cows - but that if they are about to be killed then this does not matter.

Sheep slaughter

The majority of sheep are stunned with a head-only electrical stun. The operator places a pair of electric tongs on either side of the animal's head and an electric current is passed through the brain - supposedly causing a temporary loss of consciousness.

The MHS says that the interval between stunning and knifing can be as high as 70 seconds for sheep. Another study found that the average interval was 21 seconds. Sheep take an average of 14 seconds to lose brain responsiveness if both carotid arteries (the major arteries that supply blood to the head) are cut. UK law only requires one carotid artery to be cut and in this case sheep take an average of 70 seconds to lose brain responsiveness. Yet an electric head-only stun only lasts between 20 and 40 seconds.

Viva! estimates that 4 million may regain consciousness each year before they die and we have video footage showing sheep regaining consciousness as they bleed to death. If only one carotid artery is cut, sheep may not be dead after the required 20 second bleed out time and they will therefore be skinned alive.

Researchers at Bristol University found that after an electric stun, sheep are not able to feel pain but they are have periods of being fully aware of their surroundings i.e. they can still feel fear and they are conscious whilst hanging upside down on the killing rail, bleeding to death. They could not prove whether the electricity has an immediate effect and Dr Harold Hillman, Director of the Unity Laboratory of Applied Neurobiology, says that when animals are stunned, they suffer extreme pain. They are unable to cry out or move because the massive electric current paralyses them. His evidence is based on reports from human torture victims.

Pig slaughter

Most pigs are electrically stunned and research has shown that the inaccurate placement of the electric tongs is a big problem within the industry. Research has shown that 36% of tong placements do not span the brain as required by law. 13.3% of pigs are stunned on the snout and jaws - a position which is not recommended because animals may fail to lose consciousness. Viva! estimates that in the UK, 125,000 pigs a year will not be stunned at all because of this.

Pigs stay unconscious for an average of 42 seconds but not all pigs will be unconscious for as long as this. They take up to 23 seconds to lose brain responsiveness, meaning that the interval between stunning and knifing should certainly not be longer than 19 seconds. But MHS statistics reveal that in many abattoirs, the interval between stunning and knifing is longer than this. Viva! estimates that in the UK, approximately a million pigs will regain consciousness before they die from loss of blood. We have video footage showing pigs regaining consciousness as they bleed to death.

Says abattoir vet Gabriele Meurer, 'The slaughtermen are in such a hurry that they often don't put the electric tongs in the correct position on the pigs' heads. The pigs get only half or insufficiently stunned, wake up while they bleed and are obviously still alive and conscious when they plunge into the boiling water. Sheep are stunned just as badly.'

25% of pigs - over 2 million a year - are stunned with CO2 gas. It takes pigs up to 30 seconds to lose consciousness and during that time they will squeal, hyperventilate and try to escape. Pigs are supposed to be left in the gas chamber until the gas kills them and then 'bled out'.

The captive bolt pistol is not recommended for pigs because the brain lies deep down in the head and it is difficult to cause unconsciousness. Yet the captive bolt pistol continues to be used for pigs in a high number of low throughput premises.

Chickens, turkeys, ducks and geese

1.7 million birds a year die before they even reach abattoir - from heart failure, dislocation of the hip and having their skulls crushed when the drawers on the transporter are closed.

UK legislation states that turkeys can be shackled by their legs for up to six minutes and other birds for up to three minutes before they are killed - despite evidence showing that the procedure causes extreme suffering. Chickens and turkeys are bred to grow so fast that most suffer from painful leg problems.

Before being killed, birds' heads are supposed to be immersed in an electrified waterbath in an attempt to cause unconsciousness. Some birds defecate during stunning meaning that birds can inhale faeces when they are dipped into the waterbath. Turkeys can also suffer painful pre-stun electric shocks because their wings hang lower than their heads and can enter the bath first. Despite attempts to change the system, scientists estimate that around 6% of turkeys - or 2.1 million turkeys each year - still receive prestun electric shocks.

Birds are known to "swan-neck" - raising their heads when entering the electrical waterbath and so avoiding full immersion. This is a particular problem for ducks and geese. Any birds who are not stunned are meant to be decapitated by a 'back-up killer' whilst conscious. The killer will be working with a line speed of up to 9,000 birds an hour and any birds who are missed continue on to the neck-cutter.

Birds routinely regain consciousness before they die if they do not have a cardiac arrest when they enter the waterbath. This is because they take much longer than mammals to lose brain responsiveness. Broiler chickens have been shown to recover consciousness 52 seconds after stunning in an electrical waterbath. Hens have been shown to recover consciousness after as little as 22 seconds. This means that birds who do not have a cardiac arrest will recover consciousness after being knived. It takes chickens nearly three minutes to lose brain responsiveness if both carotid arteries are severed and around 5 minutes if one jugular artery and one carotid artery is severed. If 90% of birds have a cardiac arrest at stunning, a further 62 million birds will regain consciousness before they die from loss of blood.

14 abattoirs appear to use automatic neck-cutters which only sever one carotid artery. In this case, birds who do not have a cardiac arrest at stunning will still be alive when they enter the scalding tank. Viva! estimates that 8.4 million birds will only have one carotid artery cut and will therefore be conscious on entering the scalding tank.