With the increase in worldwide demand for meat, fast-growing species with efficient feed conversion rates – such as pigs account for a major share of the global livestock sector. In 2017, almost 1 billion pigs were reared worldwide, many in intensive production systems. These have improved the efficiency of rearing pigs and reduced the price of meat, but they have led to some concerns over animal welfare.

Welfare standards for pigs in the UK are generally higher than in other countries, with a large number of pigs also reared outdoors. 40% of sows (female pigs) in England are kept outdoors – although their offspring, which are reared for meat, will typically be brought inside for some of their growing period. Most (60%) of these will be housed in straw-based indoor systems. 3 to 4% of meat pigs are reared entirely outdoors either as free-range or organic. Contrasting heavily to the majority of other pig rearing countries where very few, if any pigs are kept outdoors and most pigs are housed indoors on slatted floors.

Welfare issues for pigs

To help unravel the differences between welfare standards we first need to understand what the key welfare issues are for pigs:

Sow stalls These are pens which are used to individually confine pregnant pigs.

The narrow pens do not allow the pigs to turn around and deprive them of many natural behaviours.

Sow stalls have been banned in the UK since 1999 and their use is limited in the EU, but they are still permitted in many other countries.

Farrowing crates Sows are typically moved into farrowing crates to give birth. These are similar to sow stalls but have space to the side for the piglets.

They help reduce piglet mortality by preventing accidental crushing by the mother, but they also restrict sow movement and prevent natural behaviours such as nest building.

In the UK and most of the EU sows may be kept in farrowing crates for up to 5 weeks. Unrestricted use is permitted in many other countries.

Tail docking This is used to prevent tail biting which is an abnormal behaviour in pigs triggered by stress.

In the UK and EU tail docking is permitted where there is evidence of tail-biting and it is commonly performed – 70% of UK pigs are docked compared to virtually all pigs in Denmark, Holland, Germany and Spain. In the US, Canada and Brazil tail docking is legally permitted without restriction.

Surgical castration This is performed to prevent boar taint (an unpleasant taste in pork).

It is permitted in the EU but must be performed by a trained person and pain killers must be given. In the UK it is not permitted under welfare labelling schemes (e.g. Red Tractor or RSPCA assured) so just 2% of male pigs are castrated. This compares with Sweden (94%), Denmark (95%), Netherlands (20%), Germany (80%) and Spain (20%). In the US, Canada and Brazil timing and the use of pain killers is not set out in legislation although Canada has a code of practice covering these points.

Differences in pig welfare regulations between countries

The table below outlines the differences in pig welfare legislation between the UK and other major pork-producing areas:

  UK EU US Brazil Canada
Tail docking permitted Restricted Restricted
Surgical castration permitted Not permitted under welfare labelling schemes
Sow stalls used X Restricted use Banned in 9 states
No farrowing crates Restricted use Restricted use
Antibiotics used for growth promotion X X
Ractopamine used (a drug which promotes leanness) X X

Source: Animal Welfare Matrix, National Pig Association

Differences between welfare labelling schemes

A number of welfare labelling schemes in the UK set voluntary higher welfare standards that exceed UK legislation requirements. The table below outlines the main differences in animal welfare standards between the UK labelling schemes.

Red Tractor Standards are very close to UK legal requirements and cover both indoor and outdoor rearing systems. Surgical castration is not permitted. Farms are regularly inspected for compliance with the standards.

Outdoor bred Sows are kept in straw bedded arks with access to outdoor paddocks for their entire productive lives. Farrowing crates are not permitted, instead the sows give birth to their litters outdoors in individual straw-bedded shelters. The piglets are reared outdoors for four weeks and they are then moved indoors for the rest of the growing period.  The indoor system may be straw based (if RSPCA assured) or otherwise they may be housed on slatted or concrete floors with minimal enrichment for the pigs.

RSPCA assured The scheme covers indoor and outdoor rearing systems. Pigs that are permanently housed indoors are given more space than minimum legal requirements and must be provided with straw for rooting and foraging. Farrowing crates are not permitted and tail docking is only permitted in exceptional cases.


Outdoor reared Similar to outdoor bred, but the piglets are kept outdoors for longer (10 weeks) before being moved into a straw-based system for fattening.


pigs in field
Free-range Both sows and piglets are kept outdoors for all their lives. Farrowing crates are not permitted and tail docking is typically not needed. pigs outside
Organic Both sows and piglets are kept outdoors for all their lives and are fed organic non-GM feed. Farrowing crates are not permitted and tail docking is prohibited. Piglets are weaned at 40 days as opposed to 21 days which is the non-organic legal minimum.

Although there are differences in welfare standards between the labels there are advantages and disadvantages to all these systems. For example, in free-range systems, it can be challenging to keep the pigs warm through winter and the pigs rooting with their snouts can cause soil erosion. Equally, it can be difficult to satisfy the behavioural needs of pigs to root in non-straw based indoor systems. There are also differences in production costs between the systems. It costs more to raise an organic pig, than a free-range pig, which is more expensive to rear than an indoor housed pig. This has an understandable impact on the price consumers pay for the meat.

ADAS supports businesses in overcoming the challenges they face as they strive to make continuous improvement in farm animal health and welfare. We deliver a wide range of consultancy, research and training in relation to the health and welfare of all major livestock species (including cattle, sheep, pigs and poultry), working to improve stock performance, ensure consumer needs are met and enhance industry reputation, both within the UK and globally.

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For more information on ADAS services, please visit our Animal Health and Welfare Services page.