Pig welfare

Good animal welfare depends on three components:

• Physical well-being
• Mental well-being
• Natural living.

In intensive pig farms all three of these are compromised by periods of confinement in cages, barren environments and mutilations. Pigs also suffer during long distance transport for further fattening and slaughter.

Welfare issues for pigs

Housing of breeding sows

Sow stalls

In much of the world it is common for a pregnant sow to be kept in a sow stall (also called a 'gestation crate') for the whole of her 16-week pregnancy. A sow stall is a metal cage – usually with a bare concrete/slatted floor – which is so narrow that the sow cannot turn around, and she can only stand up and lie down with difficulty.

Sow stalls deprive pregnant sows of almost all natural behaviours; they cannot explore, exercise, forage or socialise. Most will never go outside in their lives. Pigs are naturally curious animals who spend much time exploring their environment and searching for food. Keeping sows in cages means they suffer from boredom and frustration; they do not have a life worth living.

Sow stall conditions

Potentially upsetting scenes of animal suffering.

Sow stalls also increase abnormal behaviour such as sham chewing and bar-biting, indicating severe frustration and stress, and sows in crates can exhibit behaviour likened to clinical depression. Feed is often restricted during pregnancy, causing chronic hunger and increasing the level of frustration.

Sow stalls are illegal in Sweden and the UK. Their use is limited in the EU, with a partial ban enforced from 2013. However it is still permitted for sows to be kept in sow stalls from weaning of the previous litter until the end of the first 4 weeks of pregnancy. They are being phased out in certain states in the US and in New Zealand, and there is a voluntary industry agreement to phase out their use in Australia. A number of food producing companies are starting to phase them out voluntarily on animal welfare grounds, due to consumer pressure.

Farrowing crates

Shortly before she is due to give birth (referred to as ‘farrowing’), a sow is typically moved to a farrowing crate. This is similar to a sow stall except that there is space to the side for the piglets. Bars keep the sow out of the piglets' lying area to prevent crushing.

The farrowing crate

Like sow stalls, farrowing crates also severely restrict the sow’s movement and frustrate her strong motivation to build a nest before giving birth. They prevent the sow from being able to get away from her piglets, for example if they bite her teats. It is common for piglets to have their teeth ground down or clipped, without anaesthetic, to minimise biting injuries.

Piglets are weaned and taken away from their mother when they are 3 to 4 weeks old, and even earlier in some countries. In the wild, sows would continue to feed their piglets until they were around 13-17 weeks old but the females would often stay together as adults. Male pigs disperse to find a mate and start their own family group. 

Within a couple of weeks of weaning, the sow is inseminated again (often artificially) and starts her next pregnancy. Commercial sows normally produce just over 2 litters a year with around 10-12 piglets per litter. She has a breeding lifetime of about 3 years before being sold for slaughter and replaced.

Farrowing crates have been banned in Sweden, Norway and Switzerland. In the rest of the world they are widely used.

Housing of fattening pigs

Fattening pigs are bred for meat and often kept in barren, crowded conditions. This can be on slatted concrete floors without straw for bedding or rooting. These pigs have no access to outdoors and will never experience fresh air or daylight. They are unable to behave naturally and become bored and frustrated. They tend to fight and to bite each other, sometimes causing severe injury, particularly to their tails.

In addition to tooth cutting, most piglets have their tails docked to discourage tail biting. Both of these procedures are painful and performed without pain relief. Stress, illness and conflict often result when piglets are abruptly weaned and mixed with unfamiliar young pigs.

Most male piglets in Europe (but not in the UK and Ireland) are castrated. Public pressure has led to a voluntary declaration aimed at ending the surgical castration of pigs in Europe by 2018. As a first step, signatories will ensure that prolonged pain relief is used for surgical castration of pigs from 2012.

There are alternatives to crates and barren environments.

Mutilations

Tooth clipping

Soon after they are born, the teeth of piglets are often clipped. The purpose of teeth clipping is to reduce injuries caused by piglets to each other and to their mother as they fight for the best teats.

Sows don’t always have enough milk to feed all their piglets, especially if they have large litters or their bodies are in poor conditions. To ensure that at least some of the piglets survive, the strongest get preferential treatment.

The teats nearest the front of her body get the most milk. The teats towards the back of the body get progressively less. Once a piglet has established ownership of a teat, he or she will vigorously defend it.

Piglet tooth-clipping

Watching this clip may be distressing

There are alternatives to tooth clipping.

Castration

Within a week of being born, many male piglets are surgically castrated, usually without anaesthetic or pain relief. This is done by cutting the scrotum with a scalpel, pulling out the piglet's testes and cutting them off. In Europe, this is around 70% of all males, the equivalent to around 90 million piglets every year. This is a painful procedure and major welfare concern.

The main reason piglets are castrated is to prevent “boar taint”. This is a smell or taste of pork, caused by the sex hormones testosterone and androstenone. Males that are not castrated may also be aggressive and show more sexual behaviour. This may cause injury to others if they fight or mount each other and can be dangerous to farm workers if they are aggressive during handling.

Welfare issues of castration

Many piglets are castrated without any anaesthetic or pain relief (analgesics), which causes them short and long-term pain and stress. It also leaves the piglets more prone to infection from the open wound with limited immunity at such a very young age. The extra time and cost involved in pain relief means that alleviating piglets’ distress is rarely considered.

In some countries, such as Denmark and Germany, pain relief is now commonly used, but the timing of the injection is important and it should be given at least half an hour before the procedure, which may not be the case in practice. In the Netherlands CO₂/O₂ or Isoflurane is used as an anaesthetic. CO₂/O₂ is known to be aversive to pigs, so while it may make them unconscious, it is a very unpleasant experience.

In a minority of countries, such as Sweden and Lithuania, both anaesthetic and pain relief may be used. The use of both pain relief and a non-aversive anaesthetic is important when surgical castration is performed but this mutilation is causing distress to the pigs and risking their health and welfare. Switzerland has banned castration since 2010.

There are alternative practices that ensure castration is avoided completely.

In some countries pigs are reared to a heavier weight so that certain meat cuts or fat content can be produced. This means there is more risk of boar taint because the pigs reach puberty, as well as the welfare risk of them injuring each other. Where rearing entire males is not practicable there is another alternative.

Transport and slaughter

Pigs travel badly and are easily stressed by transport and by pre-slaughter handling. They do not have sweat glands and are particularly susceptible to heat stress during transport. Internationally, significant numbers of pigs die each year in transport or in lairage at slaughterhouses as a result of stress.

There are higher welfare alternatives for pig farming.

Higher welfare alternatives for pigs

There are alternative commercial systems that improve the welfare of pigs by providing a more enriched environment which allows for more natural behaviour.

Housing

Higher welfare indoor systems

Pigs are kept in groups on solid floors with straw or other material for bedding and rooting. Although there is no access to the outdoors, there is greater opportunity for natural behaviour, free movement within the pen or shed, less crowding, conflict, boredom and tail-biting. Deep bedded systems allow foraging and comfort.

Sows may still give birth in farrowing crates, but in the better systems they give birth in huts or pens.

Outdoor bred

Sows are kept outside with straw-filled huts for shelter: this is where they will give birth to their piglets. There are no sow stalls or farrowing crates.

Sows have a higher quality of life and are able to act naturally by building nests, rooting, wallowing and foraging. The piglets benefit from the free-range conditions until they are weaned. At weaning, the piglets are taken indoors and reared in extensive or intensive conditions.

Outdoor reared

Piglets are born outside (without stalls or crates) and spend around half of their lives outside (around 3 months).

Free-range

Whilst there is no legal definition of ‘free-range pork’, a voluntary industry code in the UK requires that free-range pigs have permanent access to pasture: born outside (without stalls or crates) and then reared outside throughout their lives.

In the best free-range and organic pig farms, the sows and the growing pigs are kept outside for their entire lives. The piglets stay with their mothers for longer (up to 6 to 8 weeks), mixing of unfamiliar pigs is reduced and tail-docking is not used.

Free-range sow and piglets

Alternatives to mutilations

Farming systems should be designed to fulfil the welfare needs of the animals rather than altering the animal, through physical or genetic mutilations to fit a bad system. Mutilations can and should be avoided by better breeding, appropriate enriched environments, management and nutrition.

Alternatives to tooth clipping

Breeding sows to produce smaller litters which they can feed properly can reduce injuries caused by fighting for teats. This can also reduce the number of piglets that will starve, provided the sow is properly fed.

Some breeds of sow have higher levels of fat and this can help them to maintain high levels of milk.

Keeping the sow in high welfare farrowing systems may also help. Research in Denmark found that sows in free-farrowing systems ate more food than those kept in crates and it was suggested that they were probably producing more milk. Piglets in the free-farrowing systems grew better and were heavier at weaning than those in crates.

There are fewer injuries to the sow’s teats, and to other piglets, in systems with plenty of space and enrichment such as straw. European Union rules insist that environment and stocking density should be dealt with before resorting to teeth clipping.

Alternatives to castration

There are alternative options to castrating piglets which can vastly improve their welfare:

Rearing entire males

In some countries, such as the UK, Ireland and parts of Spain, Portugal and Greece, male piglets are not castrated but are slaughtered at a younger age (with a lower weight), lowering the risk of boar taint developing in the meat that can occur during puberty. In the Netherlands this approach is also being taken, with around 70% of males now reared entire.

Although the pigs are slaughtered at a younger age, as they get close to slaughter weight, some may develop mounting behaviour. Gilts (young female pigs) are smaller than males and they can be injured during mounting, sometimes leading to lameness. Both males and females may also suffer from cuts and abrasions leading to skin lesions. It is therefore recommended that the males and females are separated to help reduce this risk.

People’s sensitivity to boar taint varies between nationalities and sexes and some argue that even those slaughtered at a younger age may have boar taint. Where this is an issue technology is being developed to detect the scent of boar taint on carcasses at the slaughterhouse. Alternatively a person sensitive to boar taint can be employed to use the human nose to detect the smell after singing a small area of meat while the carcass is on the line. However, countries currently do not agree of what is an acceptable level of ‘boar taint’ smell and the test is very subjective.

Improvac

In some countries, a vaccination called Improvac is used as an alternative to surgical castration, by delaying the maturity of pigs. The vaccination cannot be found in the meat and is perfectly safe. It is not a hormone and should not be referred to as chemical castration which is when toxic chemicals are injected into the testes directly, causing pain and irreparable damage.

As well as stopping boar taint, it also reduces aggression and sexual behaviour in the pig. Reducing mounting behaviour improves the welfare of the pigs being mounted who are often not able to escape from it. Care needs to be taken though to minimise pain or stress to the pig while it is administered, as with any vaccination. It has been shown that the use of Improvac reduces the use of antibiotics and reduces piglet mortality by 1.5% (Colruyt Group) in comparison to surgical castration.

Farmers that use the vaccination report to have improved growth performance and also feel their working environment is safer as pigs are calmer and more predictable.

Future solutions

In the future it may be possible to select to breed from pigs which have lower levels of boar taint, and reduce the presence of the two main hormones responsible. This is a long term solution and would take 5 to 10 years to work, and aggression between the males would still need to be controlled.

An EU voluntary ban on castration for 2018

Public pressure has led to a voluntary declaration aimed at ending the surgical castration of pigs in Europe by 2018. As a first step, signatories will ensure that prolonged pain relief or anaesthetic is used for surgical castration of pigs from 2012. The countries currently signed up include Belgium, Germany, Spain, The Netherlands and Denmark.