In Australia, most pigs are housed in intensive indoor systems. In these intensive systems, pigs may be confined and raised in barren environments which leads to a higher risk of pigs experiencing poor welfare outcomes. Of particular concern are issues associated with the confinement of sows in sow stalls and farrowing crates where sows are unable to perform natural motivated behaviour, such as nesting or interacting socially with other pigs or their piglets. The RSPCA opposes housing systems that confine pigs for any extended period, including the use of sow stalls and farrowing crates.
What is a sow stall?
A sow stall, also known as a gestation stall, is a metal-barred crate that houses a single sow (female breeding pig) for part of her 16‑week gestation (pregnancy). A standard sow stall is only 2m long and 60cm wide. This is just enough space for the sow to stand up and take a step forward or backwards, but she is unable to turn around. The floor of the stall is usually concrete, with a slat-covered trench to catch urine and faeces at the rear. The Australian pig industry 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 by 2017. It is estimated that around 80% of pregnant sows in Australia are now housed in groups. Where sow stalls are still in place, regulation requires that they not be used for more than 6 weeks during gestation.
What is a farrowing crate?
A farrowing crate, also known as a ‘piglet protection pen’, is a metal-barred crate that is similar in size to a sow stall but slightly narrower. The sow is moved into the farrowing crate around a week before farrowing (giving birth) and is kept there until her piglets are weaned at about 3–4 weeks of age. The crate has an area around it for piglets to move into and avoid being accidently crushed by their mother. 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. Farrowing crates are used almost exclusively in all indoor intensive housing systems in Australia.
In extensive housing systems, instead of using farrowing crates, pregnant sows are usually housed in groups and moved to farrowing huts where they remain until their piglets are weaned. However, only a small proportion of pigs in Australia (less than 10%) are housed in these extensive semi-outdoors or free-range systems. To understand more about the difference between ‘free range’, ‘outdoor bred’, ‘bred free range’ and ‘sow stall free’, click here.
What are the welfare issues with sow stalls and farrowing crates?
Sows are intelligent and social animals, with a complex range of behaviours and needs. When confined, sows are unable to perform natural and motivated behaviours, such as foraging, or interacting socially with other pigs. As a result, confined sows can show higher incidences of aggressive behaviours and abnormal behaviours, such as stereotypies (e.g., repetitive bar biting or head swaying) . These behaviours are considered to occur when pigs are attempting to cope in an inappropriate environment and are indicative of poor animal welfare outcomes [2, 3]. Confinement can also cause sows’ muscles and bones to deteriorate, leading to sows having difficulty standing up or lying down due to lack of exercise .
Pregnant sows, just prior to farrowing, are highly motivated to engage in natural nesting behaviours (nest seeking and nest building), which they are unable to do in farrowing crates where they can’t move freely and are not provided with 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 aggression [1, 4]. In addition, stress in sows during certain stages of gestation has been associated with poor reproductive outcomes (e.g., embryo mortalities and decreased litter size) and can have long lasting negative effects on surviving piglets’ development (e.g., increased pre-weaning mortality, increased fear response, and aggressive behaviours towards other pigs) .
What are the available alternatives to farrowing crates?
There are several alternative farrowing systems to traditional farrowing crates, where sows may be confined for a shorter period or not confined at all. Temporary crating systems confine sows immediately prior and during farrowing, as well as during the first few days after farrowing but are then opened to allow sows more freedom to move. These temporary crating systems confine sows during this time to minimise the risk of piglet mortality due to crushing, which is most likely to occur during the first two-to-three days after farrowing . However, the period where the sow is fully crated is also the period where the sow’s nest seeking and nest building behaviour is frustrated due to the inability to move around and, often, lack of access to nesting materials.
Sows in free-farrowing systems, where they are not confined, have been shown to display less abnormal behaviours and less pain during farrowing [7, 8, 9]. Providing sows freedom to move during farrowing and lactation also encourages maternal interactions with piglets and may encourage more natural nursing and weaning of piglets . Providing sows with suitable nesting material is critical for sow welfare. For example, providing straw to sows prior to farrowing so that they can perform nesting behaviours can decrease stress and pain levels in sows, as well as improve piglet survival and development [11, 12].
Current available alternative farrowing systems are still associated with slightly higher piglet mortality rates than traditional farrowing crates, however, they can significantly improve sow welfare during gestation, farrowing and lactation until weaning [13, 14]. The improvements in sow welfare can also benefit piglet welfare long term, improving piglet development and behaviour (e.g., increased weight gain and decreased aggressive damaging behaviours towards other pigs), which can lead to improved production performance overall .
What is RSPCA’s position on sow stalls and farrowing crates?
The RSPCA is opposed to the use of sow stalls and farrowing crates because of the restrictions and adverse effects that these housing systems have on the movement, social interactions and behaviour of sows. The RSPCA supports the Australian pig industry’s voluntary phase out of sow stalls to housing systems where sows are housed in groups. Sows can be successfully housed in groups, provided they are properly managed and have sufficient space and environmental enrichment.
The quality and quantity of the available space provided to sows in any farrowing system is critical to ensuring they receive meaningful welfare benefits. There are alternative farrowing systems available that provide sows more freedom to move as well as nesting and bedding material. Alternative farrowing systems should balance the welfare needs of sows and piglets, by providing sows freedom to move and perform natural nesting and maternal behaviours, while also protecting piglets and minimising the risk of piglet mortality. While temporary crating systems have some welfare benefits, they still confine sows during the critical time period prior to, during and immediately after farrowing where sows are most motivated to perform nest-seeking and nest-building behaviours as well as maternal behaviours towards their piglets. For alternative farrowing systems to meaningfully improve sow welfare, they should not confine sows at any point during gestation, farrowing, lactation until weaning, as well as provide suitable nesting material.
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