The country's butchers are reporting a good supply of local hams for Christmas, reports Timaru Herald, despite recent warnings of shortages.

The soaring cost of feed grain and reduced pig numbers in New Zealand and overseas have caused international pork prices to rise as supply dwindled.

It has led to warnings from the pork industry earlier this week that Christmas ham could be in short supply.

Earlier this week, pork producers mounted a challenge to pork imports at the Court of Appeal, according to Dominion Post.

Their case follows new rules that allow imports of cheaper foreign cuts of pig meat. The imports remain on hold while the New Zealand Pork Industry Board action continues.

The board wants to stop imports of raw foreign pork from countries with the devastating pig disease, porcine reproductive and respiratory syndrome (PRRS).

New Zealand is one of a handful of countries that does not yet have the disease, which does not affect humans but can cause miscarriages and still births in pregnant sows and stunts growth and can be fatal to piglets, reports Dominion Post.

Raw pork was imported for a few years in the late 1990s and early 2000s but more recently, only cooked or treated pork has been imported in response to research that suggests the disease might be spread if raw pork from animals carrying the disease was fed to pigs.

Later the director general of agriculture approved an import health standard that allowed raw pork imports to resume if in 'consumer-ready' cuts of 3kg or less.

The Pork Industry Board says the proper process was not followed in the way the new health standard was developed. Its arguments failed in the High Court but its appeal against that decision is being heard in the Court of Appeal this week.

The former Agriculture and Forestry Ministry - now the Primary Industries Ministry - says the health standard means the risk of spreading the disease into the pig population here is virtually nil.

However the Pork Industry Board disputes the science the health standard is based on and says it does not manage the risk, concludes the Dominion Post report.

Radio NZ has reported that pork industry lobbyists from the US recently visited New Zealand and Australia, calling industry concerns unscientific and urging both countries to remove all restrictions on American pork.

The lobbyists said the importation of fresh, chilled and frozen pork has never resulted in an outbreak in a country which is PRRS-free and said pork should be included in the Trans-Pacific Partnership trade negotiations.

Massey University pig epidemiologist, Dr Eric Neumann, says New Zealand pig farmers already compete with imported pork on a daily basis and 45 per cent of the pork consumed in the country is from an imported source.

He told Radio NZ: "It's an industry that has been and will continue to be prepared to deal with import pressure.

"But it is one of the four of five countries in the world that don't have this disease and it seems prudent to do everything you can to make sure it doesn't come in."

Dr Neumann added that people must not lose sight of what a devastating disease PRRS is to pigs.

Further Reading Find out more information on Porcine Reproductive Respiratory Syndrome (PRRS) by clicking here.