BEIJING - CHINA has vowed to wipe out the 'dark' trade of adding the chemical melamine to animal feed, with farm officials claiming only a fraction of feed businesses have used the banned substance that has killed children.

The Ministry of Agriculture announced the drive against melamine use in feed, following weeks of product recalls after the chemical was found at above mandated levels in mainland-produced eggs and related products sold in China, Hong Kong and abroad.

Public alarm has forced egg prices to plummet in local markets, and wholesalers have refused stock not carrying melamine inspection certificates. Breeders have slaughtered many thousands of now-unprofitable chickens.

The egg scare has come on the heels of an even-wider scandal over milk adulterated with the industrial chemical to fool quality checks. Four children have died and many thousands been hospitalised from its use in baby milk formula.

There have been no reports of illness from the relatively low levels detected in eggs.

At a meeting on Saturday, Chinese agricultural officials defended themselves against accusations of inaction over melamine but also vowed to stamp out its illict use in the food sector.

?Thoroughly trace the sources of melamine, wipe out melamine sales networks and resolutely crush the dark dens of making and selling animal feed containing it,? the meeting ordered, according to a report on the Ministry website (www.agri.gov.cn).

?The Ministry of Agriculture demands the strictest standards, the most resolute stance and the sternest measures to investigate and punish this unlawful activity,? stated the report, which appeared late on Saturday.

But the agricultural officials also sought to defend themselves against claims that they ignored the problem.

Melamine is a compound legally used in making plastic and fertilisers, but with its high nitrogen levels it can also be added to food to cheat nutrition tests measuring protein, which is also high in nitrogen.

Last year, Chinese-made pet food ingredients adulterated with the chemical led to deaths and sickness of cats and dogs in the United States, and China?s Ministry of Agriculture announced rules on testing its presence in animal feed.

Since the US pet food problem, Chinese inspectors have checked 250,400 animal feed businesses and farms, and found melamine in 2.4 per cent of animal feed and feed ingredients tested, the report said.

But with the egg scare reinforcing consumer worries at home and abroad about China?s product safety, officials promised a renewed crackdown.

?Strike hard against those who illegally add melamine to animal feed,? the meeting urged.

?There can be no appeasement or concessions.? -- REUTERS