The majority of Australian pigs continue to be housed in intensive indoor systems. The close confinement of pigs in indoor systems raises welfare concerns because the lack of freedom and barrenness of the surroundings can lead to stress, injury and abnormal behaviours.
The RSPCA is especially concerned about the welfare issues associated with use of sow stalls and farrowing crates in these systems. Pigs that are housed in sow stalls and farrowing crates have no opportunity to engage in natural behaviour or interact socially with other pigs.
What is a sow stall?
A sow stall, also known as a gestation stall, is a metal-barred crate that houses a single sow for part of her 16‑week pregnancy. A standard sow stall is just 2m long and 60cm wide. This is just enough space for the sow to stand up in, but she cannot turn around and can only take a short step forward or back. The floor of the stall is usually concrete, with a slat-covered trench for manure at the rear. The Australian pig industry has committed to voluntarily phasing out sow stalls after the first 5 days following mating (where the sow is confined to a mating stall) in favour of group housing for pregnant sows. It is estimated that around 80% of pregnant sows in Australia are now group housed. Where sow stalls are still in place, regulation requires that they not be used for more than 6 weeks in any gestation (pregnancy) period.
What is a farrowing crate?
A farrowing crate, also known as a piglet protection pen, is a metal-barred pen that is similar in size to a sow stall but slightly narrower. The sow is moved into the farrowing crate a week before farrowing (giving birth) and is kept there until the piglets are weaned at about 3–4 weeks of age. The crate has an area around it that the piglets can move into to avoid being crushed by the sow. After weaning the sow may be placed in a mating stall (similar to a sow stall but used for artificial insemination of the sow) for up to 5 days and then returned to group housing.
Only a small proportion of Australian pig producers use systems (less than 10%) , such as group housing in large semi-outdoor shelters or paddocks (to understand the difference between ‘free range’, ‘outdoor bred’, ‘bred free range’ and ‘sow stall free’ click here). Farrowing crates are not used in extensive housing systems; instead pregnant sows are housed in groups and moved to farrowing huts where they remain until their piglets are weaned.
The pig industry argues that mating stalls are necessary to avoid aggression between sows that can result in injury and miscarriage. Farrowing crates are used to maximise survival of piglets by preventing them from being accidently crushed by the sow.
What are the welfare issues with sow stalls and farrowing crates?
Pigs are intelligent, social animals, with a complex range of behaviours and needs. Pigs that are confined in sow stalls have no opportunity to engage in exploratory and foraging behaviour, or to interact socially with other pigs. As a result, they show high levels of stereotypical behaviour (repeating the same action, such as biting the bars of the stall and swaying their heads) and unresolved aggression .
Pregnant sows are highly motivated to engage in nesting behaviours (nest seeking and nest building), but they are frustrated from carrying out this behaviour in farrowing crates, which do not allow them to walk or move freely and do not provide bedding or nesting material. Farrowing crates have been shown to increase stress and impair the sows’ ability to thermoregulate (control body temperature) during farrowing, increasing the risk of heat stress, as well as being associated with an increased number of stillbirths and negative maternal behaviours such as sow aggression [2, 3].
Sow stalls and farrowing crates can also cause physical problems for the sows. Because they are unable to exercise, their muscles and bones deteriorate and they may have great difficulty in standing up or lying down .
What is RSPCA’s position on sow stalls and farrowing crates?
Pregnant sows can be successfully housed in groups, provided that they are properly managed and have sufficient space and environmental enrichment. Alternatives to sow stalls include straw yards with individual or electronic feeders to regulate food intake. There are also alternatives to farrowing crates, including farrowing pens, which provide bedding and allow more movement, or farrowing huts as used in extensive housing systems.
The RSPCA is opposed to the use of sow stalls because of the restrictions and adverse effects that this housing method has on the movement, social interactions and behaviour of sows. The RSPCA supports the Australian pig industry’s move to phase out the use of sow stalls to a production system where pregnant sows are housed in groups. The RSPCA supports the use of farrowing systems that provide freedom of movement and meet the sows’ and piglets’ behavioural and physiological needs; this includes the use of bedding to allow nesting behaviour. Sow stalls and farrowing crates are not permitted under the RSPCA Approved Farming Scheme standards for pigs. Visit the RSPCA Approved Farming Scheme website for more information.
 Pedersen L (2018) Advances in pig welfare: overview of commercial pig production systems and their main welfare challenges. Herd and Flock Welfare, Ch1 pp3-25.
 Baxter E, Lise Andersen I and Edwards S (2018) Advances in pig welfare: sow welfare in the farrowing crate and alternatives. Herd and Flock Welfare, Ch2 pp27-72.