Editing Intensive pig farming (section)

===Sow breeding systems===
Organized campaigns by animal activists have focused on the use of the gestation crate, such as the 'gestation crate' and farrowing crate. The gestation crate has now been banned in the UK, certain US states, and other European countries, although it remains part of pig production in much of the US and European Union.

The sows selected for breeding will be confined in a gestation crate. Hogs (males) are kept confined in caged crates of the same size for the duration of their lives in order to have their sperm repeatedly extracted by workers. In an intensive system, the sow will be placed in a crate prior to insemination and will stay there for at least the start of her pregnancy, depending on each country's laws and local regulations. The typical length of the sow's pregnancy is 3 months, 3 weeks, and 3 days. In certain cases, sows may spend this time in the crate. However, a variety of farming systems are used and the time in the crate may vary from 4 weeks to the whole pregnancy.

There is also current controversy and criticism of 'farrowing crates'. A farrowing crate houses the sow in one section and her piglets in another. It allows the sow to lie down and roll over to feed her piglets, but keeps her piglets in a separate section. This prevents the large sow from sitting on her piglets and killing them, which is quite common where the sow is not separated from the piglets.<ref>[http://www.livestocktrail.illinois.edu/swinerepronet/paperDisplay.cfm?ContentID=6266 “Piglet Losses,”] University of Illinois Extension, November 5, 2003.</ref> Sows are also prevented from being able to move other than between standing and lying. Some models of farrowing crates may allow more space than others, and allow greater interaction between sow and young. Well-designed farrowing pens in which the sow has ample space can be just as effective as crates in preventing piglet mortality.<ref name=ciwf08/> Some crates may also be designed with cost-effectiveness or efficiency in mind and therefore be smaller.

Authoritative industry data indicate that moving from sow stalls to group housing added 2 pence to the cost of producing 1&nbsp;kg. of pigmeat.<ref name=ciwf08/>

Many English fattening pigs are kept in barren conditions and are routinely tail docked. Since 2003 EU legislation has required pigs to be given environmental enrichment and has banned routine tail docking. However, 80% of UK pigs are tail docked.<ref name=ciwf08/>

In 2015, use of sow crates was made illegal on New Zealand pig farms.<ref name="NZ_Herald_10691325">{{cite news |url=http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=10691325&ref=facebookheadlines |title=Sow crates to be phased out by 2015 |date=1 December 2010 |newspaper=[[The New Zealand Herald]] |access-date=4 October 2011}}</ref>