The domesticated pig is a subspecies of the wild boar. They are highly intelligent, sociable animals with an amazing sense of smell. They were originally native to Europe and parts of Asia but have, over the centuries, been introduced to many parts of the world.
In natural conditions, pigs live in small social groups, consisting of a few sows with their young. Sows are caring, gentle and dedicated mothers who spend their time foraging, rooting and nest building. Sows compete to establish hierarchies, but love spending time with each other.
In the wild, sows would normally 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.
In commercial systems, domesticated pigs are divided between fattening/meat pigs and breeding sows, both with similar behavioural needs. Sows have an average lifespan of 20 years but in commercial settings are usually culled after 3 to 5 litters, meaning around 2-3 years of age.
Discover more about how to provide meat pigs and sows with a better quality of life below.
Providing meat pigs with a better quality of life
Easy access to good food and water
Sufficient space to socialize, exercise and rest
Material to root around in
Opportunities to socialise with other pigs
A life free from painful procedures
Sufficient light and shelter
Ability to express their inquisitive and fun characteristics
Providing sows with a better quality of life
Easy access to good food and water
Sufficient space to exercise and rest
No confinement in cages
Material for nest building and to root around in
Opportunity to care for their young
Opportunities to socialise with other sows
Sufficient light and shelter
Commercial pig production
Around 1.4 billion pigs are slaughtered annually for meat worldwide. The majority of these are in East Asia, particularly China, which rears around half of the world’s pigs. This is followed by the EU, North America, Vietnam and Brazil.
At least half of the world’s pigs are produced in intensive systems where sows are often confined in narrow crates, unable to move freely when they are pregnant and nursing their piglets. Even in the EU where a partial ban on sow stalls is in place (as sows should be in groups after the first 4 weeks of pregnancy), the average sow still spends around half of her life in a cage.
The piglets reared for meat are often mutilated without appropriate pain management and kept on concrete slats without bedding. Pigs also suffer during long distance transport for further fattening and slaughter.
Intensive Pig Farming
Intensive pig farming results in an increasing number of welfare problems for sows and meat pigs.
SOWS TEND TO BE:
Kept in individual sow stalls during part of their pregnancy, and farrowing crates to give birth and during lactation. Both stalls and crates restrict the sow’s movement so that she is only able to stand up and lie down; she is unable to turn around or walk more than one or two steps.
Kept in barren environments with no opportunity to root or build a nest.
Fed a small quantity of high nutrient-dense feed (during pregnancy) which, whilst satisfying her nutrient requirements, does not provide satiety – so she feels physical hunger.
Bred to produce large litters.
MEAT PIGS TEND TO BE:
Reared in barren, overcrowded environments usually with fully slatted flooring, without bedding.
Subjected to the routine mutilations of teeth-clipping, tail-docking, and castration.
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 which means they suffer from boredom and frustration.
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.
Sow stalls are illegal in the UK, Norway and Sweden and phased out in Germany by 2030, and 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.
Several producers are starting to phase out sow stalls voluntarily on animal welfare grounds, due to consumer pressure.
Shortly before she is due to give birth (referred to as ‘farrowing’), a sow is typically moved to a farrowing crate where she will stay until her piglets are weaned (often at only 21 days of age).
The farrowing crate is a narrow metal cage which restricts the sow’s movements and hinders her ability to interact with her piglets. Bars on the side of the crate give the piglets access to the sow’s teats to feed and prevents them from risk of crushing by keeping them away from the sow as she lies down.
Farrowing crates severely restrict the sow’s movement and her strong motivation to build a nest before giving birth. They also prevent the sow from being able to get away from her piglets, for example if they bite her teats. Piglets are weaned and taken away from their mother when they are 3 to 4 weeks old, and even earlier in some countries.
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 2-3 years before being sold for slaughter and replaced.
Farrowing crates have been banned in Sweden, Norway, and Switzerland, and are being phased out in Germany and Austria, but are widely used in the rest of the world.
In intensive systems, sows are kept in barren environments with no opportunities to explore their environment, root around or build a nest.
Their strong maternal instinct to build a nest for their young has survived domestication and involves increased activity, such as searching for nesting materials, digging, and rooting out a shallow hollow, and constructing a suitable nest.
Their ability to fulfil these natural behaviours depends on their space allowance, the possibility of movement and access to suitable nesting materials - all of which are insufficient in farrowing crates which causes stress and frustration.
Feed is often restricted during pregnancy, causing chronic hunger, and increasing the frustration levels of pregnant sows.
In conventional feeding systems, pregnant sows are fed a concentrated diet made of 2-3kg of food a day, normally as one meal.
This provides little opportunity to ensure satiety and fulfil foraging needs, and leads to hunger which is associated with increased levels of aggression, physical activity, and the development of stereotypic behaviour (e.g. bar-chewing).
Sows are increasingly bred to be hyper prolific, to further increase the number of piglets born per litter. However, larger litters can lead to higher piglet mortality and can also compromise the welfare of the sow.
Litter sizes can be as large as 17 piglets and can cause pain and fatigue at the time of farrowing, as well as some piglets needing to be fostered by other nurse sows, breaking the mother-offspring bond.
Fattening pigs are bred for their meat and are generally housed in barren, overcrowded sheds, often on slatted/concrete floors, without any comfortable bedding or material to root around in such as straw.
They have no outdoor access, and their confined, barren conditions means they are unable to perform natural behaviours and become bored and frustrated.
In overcrowded environments, they are also unable to move away or hide from other pigs, so they tend to fight and bite each other, sometimes causing severe injury, particularly to their tails.
Most piglets have their tails docked to prevent tail lesions due to tail biting, which is a painful procedure and generally performed without pain relief.
Stress, illness and conflict leading to tail biting often result when piglets are mixed with unfamiliar young pigs, in environments that prevent natural behaviours, leading to boredom and frustration.
Routine tail docking in pigs is currently banned by EU legislation but a series of recent audits carried out by the European Commission to assess the implementation of the Pig Directive have highlighted that in almost all EU countries, over 90% of meat pigs are routinely tail docked.
Within a week of birth, many male piglets are surgically castrated (although not in the UK and Ireland), usually without appropriate anaesthetic or pain relief, causing short and long-term pain. It also leaves the piglets more prone to infection from the open wound with limited immunity at such a very young age.
The main reason piglets are castrated is to prevent “boar taint”. This is a smell or taste of pork, caused by the sexual 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.
In some countries, pigs are reared to a heavier weight so that certain cuts of meat or fat content may 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 are other alternatives to surgical castration, such as Improvac.
Pigs do not have sweat glands and are particularly susceptible to heat stress during transport and pre-slaughter. Significant numbers of pigs die each year in transport or in lairage at slaughterhouses due to stress.
In some slaughterhouses, pigs are pre-slaughter stunned using a mixture of CO2 at a high concentration which has been shown to be severely detrimental to pig welfare, as it causes a feeling of burning to the pigs’ lungs before they lose consciousness.
Higher welfare pig production
There are alternative commercial systems that improve the welfare of pigs by providing a cage-free and more enriched environment which allows for more freedom of movement and natural behaviours.
Compassion will continue to work with industry to improve the welfare of sows and meat pigs through it's various corporate engagement programmes.
If you want more help or information, please contact the Food Business team.
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