The pork industry wants more time to comply with a new animal welfare code that would outlaw sow stalls and farrowing crates.
It says that if a ban is rushed in, a drop in local pork supply will be filled by pork from countries that allow stalls and crates.
Submissions on a new code that would stop the use of stalls during pregnancy and crates afterward close next week.
The Pork Industry Board, representing 360 pig farmers who produce 46,000 tonnes of pork a year, says the draft code asks too much of the industry.
The main proposals are to limit sow stalls to four weeks post-mating from the end of this year, then to prohibit them altogether from "a date to be determined", which could be as early as 2017, and to limit crates to four weeks post-farrowing from the date the code is issued.
The code was urged by the Government last year following a furore when piggery scenes were televised by animal welfare activists.
An Agriculture and Forestry Ministry analysis of the economic effect of the code estimates banning stalls and crates would lift pork prices 4.4 to 4.7 per cent and would cost farmers $266 a sow.
The industry is getting its own analysis done by independent consultant Nimmo Bell.
Board chief executive Sam McIvor said farmers were willing to change their practices.
"We appreciate there has to be a better way, but it also has to be appreciated that we work in a global market.
"You can push us as hard as you like, but history has shown that when New Zealand product isn't put in the marketplace it is simply replaced by imports."
These would come from North America.
"If you genuinely have an issue with welfare, you should know it is likely the imports will be from sows in stalls for the full gestation."
Pregnant sows were kept in stalls because they became aggressive and lashed out at other pigs and piggery workers. They were at their worst in the first four weeks. At farrowing, they were kept in crates to stop them rolling over and crushing their piglets.
Europe's piggeries were required to remove sow stalls by 2013, though most would not make that date. Nowhere in the world were farrowing crates banned and no moves were under way to change that.
For the half of New Zealand's pig farmers using stalls and crates, the change to open housing would take time, Mr McIvor said. Finance and building consents would be needed.
Pig farms were small and under-valued and did not have the equity to easily afford new robust, pig-proof, buildings. Consents would have to be notified and then a lengthy process could be expected as farmers addressed misperceptions over odour.
Sows were easier to handle in stalls and crates. Without them more staff would also be needed. Skilled local staff were hard to find and more would be needed from overseas.
Mr McIvor could not say how much extra time the industry would need to comply with the proposed code without doing itself economic harm. He hoped the Nimmo Bell analysis would provide an answer.
In the meantime, the industry was moving to ensure farmers were looking after their pigs. It had contracted Assure Quality to audit farmers annually.
A survey last year showed shoppers were not prepared to pay the extra cost of buying free-range pork. At Christmas, the demand for New Zealand ham was stronger than it had ever been.
"Consumers have given us a message about welfare, but also, it is clear they are fiercely loyal to their local industry.
"They are knowledgeable about imports, but I suppose it is a bit of `better the devil you know than the devil you don't'."
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