NZPork said its new proposals represented "the most significant changes to the industry in a generation".
They include:
• Reducing the maximum time farrowing crates can be used from the current 33 days to no more than seven days, and no more than four days after sows give birth
• Ensuring all sows are provided with nesting material before farrowing
• Increasing the minimum space allowance for grower pigs by 13 per cent
• Eliminating the use of mating stalls for housing sows
NZPork said it also sought to retain "an outcome-based approach" to deciding when piglets should be weaned, rather than the "inflexible" minimum weaning age proposed by NAWAC.
Listen to Jamie Mackay interview NZPork chair Eric Roy on The Country below:
NZPork said the changes would place New Zealand's standards beyond those required in the United Kingdom, European Union, United States, Canada, Australia and China - which collectively produce most of the world's pork and supply most of the pork exported to New Zealand.
While NAWAC was an expert committee, Kleiss believed it didn't understand pig farming the way NZPork did.
"NZPork has worked with our technical advisors to develop alternative proposals, which are based on a rigorous in-depth review of contemporary pig welfare science and good practice.
"They are substantial, meaningful and collectively demonstrate welfare standards that go beyond all major pork-producing countries."
Although NZPork's alternatives to NAWAC's proposals would be costly to implement, they had the support of most commercial pig farmers, Kleiss said.
"NAWAC has not considered the substantial cost to industry of its own proposals, which hasn't been helped by their inability to agree on what represents minimum standard in some cases."
NZPork believed NAWAC's proposals could cost around $10,000-$20,000 per sow, on a standard farrow, to finish operation - the equivalent of more than 20 years of profit, Kleiss said.
"Our own industry proposals will still need government support along with adequate time to implement change.
"We urge the Government to work with the pig farming sector to confirm the industry-supported alternative standards and agree to an implementation plan that is achievable for pig farmers and ensure their farms remain financially viable."