There were 5.36 million breeding sows in the United States as of 2016, out of a total of 50.1 million pigs. Most pregnant sows in the US are kept in gestation crates. The crates are banned for new installations only in Canada, so many sows are still confined in Canadian pig breeding facilities. They are banned in the United Kingdom and Sweden, and in nine states in the US (Arizona, California, Colorado, Florida, Maine, Michigan, Ohio, Oregon and Rhode Island). However, farrowing crates, in which female breeding pigs can be kept for up to five weeks, are not banned.