New Zealand has announced a complete ban on the use of sow stalls by the end of 2015.
Under New Zealand's Animal Welfare (Pigs) Code of Welfare 2010, which came into effect on Friday, the use of sow stalls will be limited to four weeks by 2012, and banned completely by the end of 2015.
Australia's Pig Code requires that the use of sow stalls be limited to six weeks by 2017, with no indication that their use will be banned.
Sow stalls are used by the pork industry to house pregnant pigs for all or part of their 16-week pregnancy. The stall dimensions permitted by Australia 's Pig Code allow sows to be kept in stalls only slightly bigger than their bodies.
Scientific research shows that sows kept in stalls suffer severe behavioural impairment, such as stereotypies (repeated behaviour such as bar biting that lacks any obvious function) which are an indicator that the sow is having trouble coping with her environment.
Sows kept in stalls suffer significant leg problems, resulting in lameness, and they are virtually unable to express natural pig behaviours, such as nesting and rooting.
There are many alternatives to sow stalls that are widely accepted to be better for pig welfare, including family pens and ecoshelters. These systems also have lower capital costs than intensive indoor farming.
New Zealand's Agriculture Minister David Carter said: "The growing unease of many New Zealanders about the use of sow stalls, which I share, made it clear that change was necessary. The science also supports this.
"The reality is, worldwide there is increasing opposition to highly intensive systems of pig farming and New Zealand has a role to play in leading the way.
"Dry sow stalls are currently in use in most countries, including [the US], Canada and most of the European Union. The Australian pork industry recently voted to pursue the voluntary phasing out of sow stalls by 2017.
"The new code confirms New Zealand's position as a world leader on animal welfare and demonstrates the priority this Government places on it.”
Brian Sherman, managing director of Animal protection institute Voiceless, called on the federal Agriculture Minister, Senator Joe Ludwig, to revise Australia 's Pig Code immediately and to follow New Zealand 's lead.
“ New Zealand 's Agricultural Minister has said the science clearly does not support the use of sow stalls,” Mr Sherman said.
“I call on minister Joe Ludwig to immediately revise the Pig Code and to accept what science clearly tells us: sow stalls are bad for pig welfare.”
Last month, Australian Pork Ltd, the peak body for pork producers, voluntarily decided to ban sow stalls by 2017.
Coles has announced that it will stop sourcing pork from farms that use sow stalls by 2014, and, this year, the Tasmanian government also announced a state ban on sow stalls.
“When Australia 's Pig Code was reviewed in 2007 the federal government concluded that the science did not support getting rid of sow stalls altogether,” Mr Sherman said.
“It's clear that the government now lags behind not only industry, retailers and the Tasmanian government, but behind New Zealand as well.”
Sow stalls are already banned in Britain and Sweden , as well as in several US states.
Dr Malcolm Caulfield, a member of the Animal Welfare Advisory Committee whose recommendation to ban sow stalls was adopted by the Tasmanian government, said that “the most important aspect of the New Zealand decision is that it was reached following detailed and objective analysis of the relevant science. It is apparent from that analysis that the science regarding both welfare and reproductive performance does not support the continued use of sow stalls. The Australian pork industry continues to deny this is the case.”