What are the animal welfare issues with farrowing crates for sows?

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 farrowing crates where they are unable to perform innate and motivated behaviours such as nest building, nest seeking, or interacting socially with their piglets. The RSPCA opposes housing systems that confine pigs for any extended period, including the use of farrowing crates and sow stalls.

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. Farrowing crates are used to house female breeding pigs who are about to give birth. A female breeding pig may be either a gilt (a young female breeder pig who has not yet given birth to a litter of piglets) or a sow (a female breeder pig who has given birth to at least one litter of piglets)¹. Around a week before farrowing (giving birth), the sow is moved into a farrowing crate and kept there until her piglets are weaned at about 3–4 weeks of age. While in the crate, the sow can stand up and take a step forward or backwards, but she is unable to turn around. The crate has an area around it for piglets to move into and avoid being accidently crushed by their mother. Piglets also have access to a ‘creep area’ which provides additional heat either through a heat lamp or floor heating to keep the piglets warm. After the piglets are weaned, the sow may be moved into a mating stall (similar to a sow stall) to be artificially inseminated and kept in the stall for up to 5 days before being returned to group housing. In Australia, almost all intensive indoor housing systems exclusively use farrowing crates.

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.

Animal welfare issues with farrowing crates

Pigs are intelligent and social animals, with a complex range of behaviours and needs. Pregnant sows, just prior to farrowing, are highly motivated to engage in nesting behaviours (such as rooting, digging, turning, and carrying nest substrates), which they are unable to perform in farrowing crates where they can’t move freely and are not provided with bedding or nesting material. Farrowing crates have also been shown to increase stress and impair the sow’s ability to rest properly, 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 ​[1, 2]​.

Key animal welfare concerns ​[3]​

movement restriction:

• sows can take only a small step forward or back and cannot turn around
• sows spend more time sitting and have trouble getting up and lying down
• sows suffer injuries due to extended lying or slipping while trying to get up or lie down
• sows cannot choose to spend time away from the nest
• sows cannot choose to defecate and urinate away from the nest.

inability to perform exploratory or foraging behaviour:

• sows are unable to express an innate behavioural need to build a nest in which to give birth to their piglets – behaviours such as rooting, digging, turning, and carrying nest substrates are not possible in a farrowing crate
• sows cannot perform innate exploratory, foraging, rooting, and sniffing behaviours
• sows are likely to redirect oral behaviours (e.g., nosing, licking, biting) towards the bars of the crate and these behaviours can develop into stereotypies.

inability to perform maternal behaviour:

• sows cannot initiate social interactions with their piglets (e.g., sniffing, nosing, and grunting) resulting in reduced social contact between the sow and her piglets
• sows cannot choose to move away from her piglets and piglets may suckle without receiving any milk
• sows’ inability to perform normal maternal behaviour and resulting stress may impact piglet survival (e.g., crushing, malnutrition).

stress:

• sows unable to perform nest-building behaviour take longer to give birth which leads to stress
• sows are at high risk of heat stress when farrowing (due to intense muscular activity) and lactating (due to metabolic heat load from milk production) and find it difficult to thermoregulate when unable to easily change position or access a floor area more suitable for relieving heat stress
• sows can’t choose to move away from piglets trying to access the udder and may increasingly lie on their belly rather than on their side or attempt to get up to seek relief from the discomfort of piglets suckling at the udder.

insufficient rest/sleep:

• sows are restricted in their ability to get up, lie down and adopt a comfortable lying posture which likely disrupts the amount and quality of sleep
• sows are often in contact with the crate’s metal bars when lying on their side (lateral lying is more comfortable for pigs) resulting in discomfort, tiredness and/or frustration
• sows on uncomfortable (concrete) flooring with lack of bedding suffer from sustained pressure on bony parts of the limbs and development of pressure sores
• sows cannot rest properly on wet and dirty flooring.

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 for the first few days after farrowing but are then opened to allow the sow 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 farrowing and in the first two-to-three days after farrowing [6]. However, immediately before farrowing is also the period that a sow is most motivated to perform nest building behaviours and thus can become frustrated if unable to move around and access nesting materials. During and immediately after farrowing are the periods that sows are likely to perform comfort behaviours to ease the pain from farrowing and interact with their piglets to establish a maternal bond, which they are also unable to easily do when confined in a farrowing crate.

Alternative farrowing systems where the sow is not confined at all and is able to move freely include individual or group farrowing pens with or without group suckling of piglets (used in indoor systems), indoor farrowing pens with access to an outdoor area, and outdoor farrowing huts located in paddocks (free-range or outdoor-bred systems). Gilts/sows in free-farrowing systems, where they are not confined, have been shown to display less abnormal behaviours and less pain during farrowing ​[4–6]​. Providing freedom to move during farrowing and lactation also encourages maternal interactions with piglets and may encourage more natural nursing and weaning of piglets ​[7]​.

Providing sows with suitable nesting material is critical for their welfare. For example, providing straw 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 ​[8, 9]​. Further, to allow for innate foraging behaviour, sows in farrowing crates should be provided with appropriate foraging material that are edible and/or otherwise satisfy the sow’s need to chew, investigate and manipulate objects and substrates in her environment ​[3]​.

While alternative farrowing systems currently available are often associated with slightly higher piglet mortality rates than traditional farrowing crates, they can significantly improve sow welfare during gestation, farrowing and lactation until weaning ​[10, 11]​. The improvements in animal welfare can also benefit piglet welfare in the 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 ​[12]​.

What is RSPCA’s position on farrowing crates?

The RSPCA is opposed to the use of farrowing crates because of the restrictions and adverse effects that these housing systems have on the movement, social interactions, and behaviour of sows. The Australian pig industry should aim to phase out farrowing crates in favour of free-farrowing systems (sometimes referred to as cage-free or crate-free farrowing systems).

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 periods before, during and after farrowing where sows are most motivated to perform innate behaviours including nesting and maternal interactions with piglets. Therefore, for alternative farrowing systems to meaningfully improve sow welfare, they should not confine sows at any point during gestation, farrowing, and lactation until weaning.

The RSPCA is also opposed to the use of sow stalls because of the restrictions and adverse effects that they have on the movement, social interactions, and behaviour of sows. For more information on the animal welfare issues with sow stalls, click here.

1. For simplicity, this article uses ‘sow’ to refer to any female breeding pig.