Gestation crates are individual, concrete-floored metal stalls measuring 0.6-0.7 m (2.0-2.3 ft) by 2.0-2.1 m (6.6-6.9 ft), only slightly larger than the animals themselves and so severely restrictive that the sows are unable to turn around. The majority of breeding sows are now confined in these crates for nearly the entirety of their approximately four month (112-115 day) successive pregnancies. In typical pig production facilities, the crates are placed side by side in rows, often with more than 20 sows per row and 100 or more sows per shed.
As a result of the intensive confinement, crated sows suffer a number of welfare problems, including poor hygiene, risk of urinary infections, weakened bones, overgrown hooves, poor social interaction, lameness, behavioral restriction, and stereotypies.
Virtually immobilized in barren, restrictive gestation crates, the welfare of breeding sows is severely compromised. Without any bedding materials, sows have no thermal protection, which can cause systemic and local cold stress, and may contribute to or exacerbate injuries to skin and limbs.
Since gestation crates are barely larger than the sow’s body, the animals must urinate and defecate where they stand. As such, the concrete floors of the crates are often partially or fully slatted to allow waste to fall into a pit below. Housing the sows directly above their own excrement has been shown to expose the animals to aversively high levels of ammonia, and respiratory disease has been found to be a significant health issue for pigs kept in onfinement.
Foot and leg disorders, urinary tract infections, and cardiovascular problems are also of concern for crated sows, who additionally suffer traumatic injuries and body sores often caused by being forced to stand and lie on unnatural flooring or in residual feces and urine. Research led by Broom found 33% of crated sows required removal from production as a result of health problems,compared with less than 4% of group-housed sows.
Fortunately, public policy changes are beginning to occur around the globe. Gestation crates were first banned in Sweden and the United Kingdom, but as of January 1, 2013 they are now illegal throughout the entire European Union, although some countries are not yet compliant. In 2010, gestation crates were banned in Tasmania, and New Zealand. The pork industry has initiated a voluntary ban in the whole of Australia, and South Africa is discussing a phase-out by 2020.