Animal feed makers deliberately added an industrial chemical to their products, ignoring a year-old government rule meant to protect China's food supply, a government official said.

Inspection teams have descended on feed makers nationwide in a "punishment" campaign to ferret out those found using excessive amounts of the chemical melamine, Agriculture Ministry official Wang Zhicai said in remarks posted on the ministry's Web site and carried by state media Saturday.

Among the quarter of a million feed-makers and animal breeding farms inspected, inspectors found more than 500 engaged in illegal or questionable practices, with police further investigating 27 companies, Wang said. He likened the behavior of some of the companies to organized crime, calling them "black nests of gangsters."

"Adding melamine to feed is a criminal act and must be firmly attacked," Wang said.

His remarks were the latest by a government that is trying to appear responsive to a widening food scandal. In the nearly two months since the government first acknowledged that melamine contaminated the milk supply, the chemical has been detected in eggs, candy and other products. Its presence in feed raises fears about the safety of meat and fish.

Commonly used in plastics and fertilizers, melamine is high in nitrogen, which registers as high protein levels in routine tests of food and feed. Though experts say at low levels it does not pose a risk to human health, higher concentrations harm the kidneys.

At least four children died from drinking tainted infant formula and milk powder and tens of thousands of others were sickened. The broad array of tainted products — and the government's delayed response — has damaged public confidence at home and raised further questions about the quality of Chinese products in crucial export markets.

A little more than a year ago, China vowed to minimize the use of melamine after it was found in pet food exports that killed dogs and cats in North America in 2007. Following that, Wang, the agricultural official, said China adopted "a rigorous standard" for melamine's use — 2 parts per million.

Since the milk contamination was exposed in September, inspectors have redoubled efforts to enforce that 2007 standard, Wang said.

"Producers violating the law will be severely punished: they could have their licenses revoked and be handed over to law enforcement organs to be held legally responsible," said Wang, who heads the Agriculture Ministry's animal husbandry and livestock office.

Already, he said, inspectors have safely disposed of 3,682 tons of feed that exceeded standards.

Executives in food processing industries have said the use of melamine was widespread in China, gaining ground in recent years as prices of real protein additives climbed.

中国政府官方透露，动物饲料生产商们有意忽视一年前政府颁布的法令，公然在饲料中添加工业化学药剂，还美其名曰保护中国的食品供应。

国家农业部畜牧业和家畜负责官员王志材在其部门网站上发言说，技术检查组已在全国范围内对饲料生产商开展了一场突击检查,严格查处那些超标使用化学三氯氰胺的厂商,该发言周末被国家媒体转载.

王志材说,在对全国数百万家饲料生产商和牲畜养殖场抽查了四分之一后,发现500多家存在着可疑或违法行为,随着警方对27家公司的进一步调查,他将此行为比作是有组织的犯罪,称他们为”犯罪份子黑巢”.

“饲料中添加三氯氰胺是一种犯罪行为,必须严厉打击.”王志材宣称.

王志材的发言是政府部门开始着手对逐渐扩大的食品界丑闻进行整顿所作出的最新反应.自从政府公开承认奶类供应确实受到三氯氰胺污染后的两个月内,鸡蛋,糖果以及其他一些产品中陆续被检验出含有化学物质,饲料中含有化学物质引起了大众对肉类和鱼类食品安全的恐慌.

三氯氰胺富含大量氮元素,通常使用在塑料制品和肥料中,而在食品和饲料的常规检测中却被视为高蛋白含量.尽管专家表示低含量的三氯氰胺对人体健康无害,但浓度过高却会引起肾结石.

 迄今已有四例儿童因饮用受污染的婴儿配方奶粉,上万的儿童因此患上相应的疾病.越来越多的污染产品,政府延迟的整治措施均严重打击了国内大众对食品安全的信心,而至关重要的出口市场也对中国产品质量安全提出了很大的质疑.

2007年出口的宠物粮食质量问题导致北美大量的猫狗死亡,中国对此宣誓将三氯氰胺的使用量降低到最低,紧接着,农业部门的王志材宣布中国对三氯氰胺的使用量将严格控制在每一百万中含量为两分.

 王志材透露说自9月份曝光的牛奶污染事件后,检测人员再次对执行”2007年标准”的力度提出质疑.

“政府将严厉惩处无视法令的生产商,我们将吊销他们的生产许可证,并将之移交给法律执行机构执行法律责任.”

目前检测人员已经安全处理了超标的3682吨饲料.

食品加工业的执政人员透露说由于近几年正宗蛋白质添加剂的价格不断上涨,在中国使用三氯氰胺替代是个普遍现象,还在不断扩大.