According to Stuff.co.nz, sow stalls will be banned by the end of 2015 despite the $20 million cost to pig farmers to change their housing and it being commonly utilised overseas.

The pork industry came in for criticism when comedian Mike King switched from fronting its televised advertising to a campaign by animal welfare activists against sow stalls.

Yet the controversy does not appear to have hurt pork sales and may have improved its image.

Each New Zealander consumed about 20.6 kilos of locally produced and imported pork meat in the year to September, up 7.6 per cent from the year before and processing increased 5 per cent to 730,000 pigs.

While 45 per cent of all pig meat is imported, mostly from North America, the market share of New Zealand fresh pork is rising and the consumption of locally produced bacon had risen by 10 per cent in the past few years.

NZPork chief executive Sam McIvor said the move by the large company Kiwi to New Zealand-produced meat had helped lift the market share, but this was being driven by consumer demand for "country of origin" meat.

Mr McIvor said: "We were expecting in a recession people would go to the cheapest meat, but I think we have seen a strengthening of locally produced pork consumption. People are paying more for their meat and if this is so they want quality. There is a perception of local meat being better quality."

He said New Zealand had more outdoor pig farms than overseas and changes to the sow stalls would also be influencing buyers.

"We have gone through some stuff with animal welfare and the industry has responded. If you are a local consumer you can whack your local producer and they will respond."

Mr McIvor said other countries were lagging behind New Zealand in committing to changing sow pens.

Imports from mostly North America, Scandinavia and Australia account for about 45 per cent of the total supply of pork. Some of the extra consumption could be from shopper resistance to higher priced lamb and beef cuts.

The major challenge facing pig farmers is the cost of grain, but optimism is rising as prices drop. More grain is expected to be available on the market from a promising growing season and more grass should reduce dairy demand for grain.

Mr McIvor said the outlook for domestically produced pork was positive and more growth was expected to be made in bacon and small goods.

Pig farmers have put more money into promoting locally produced meat, including country of origin stickers, and want labelling made compulsory.