Chickens raised in China are being fed an increasing amount of antibiotics to ward off disease, according to a newspaper report.

This results in a residue of drugs in the meat and in eggs, a situation which could lead to people developing a resistance to antibiotics if they ate such food regularly, the International Herald Leader, a Chinese newspaper, said yesterday.

However, this was not a cause for concern in Shanghai, Zhang Weijian, an official with the Shanghai Livestock and Veterinary Office, said.

"We're strengthening the disinfection of livestock farms, which has reduced the incidence of poultry getting sick," Zhang said.

Breeders use legal antibiotics on livestock only when they were ill, while some herbs, with no human side-effects, are also used for treatment, Zhang said.

The city's chickens in their laying cycles are not allowed to be given antibiotics, Zhang added.

But nationwide there has been an explosion in the use of antibiotics, the newspaper said, caused by inadequate regulations and lax supervision.

The antibiotics used on one chicken cost 0.5 yuan previously, already exceeding the country's standard, but now some breeders are spending 2 yuan on increased doses, Xiao Chuanming, a Beijing expert, told the newspaper. "It is terrible." He believed breeders have a mistaken conception about antibiotics, and some drug companies just take advantage of the misconception to make more profits.

Almost half of the 210,000 tons of antibiotics produced in China each year are used in the livestock industry, the newspaper said.

A worker at a farm in Baoding City, in north China's Hebei Province, told the newspaper that its large number of chickens were kept in cramped and dark conditions and fed with antibiotics and even hormones.

The worker, surnamed Zhu, who had been at the farm for five years, said hormones were added to help the chickens lay more eggs. Zhu said he had not eaten an egg since he started work at the farm.

Last month, a premature baby was found to be resistant to a wide rage of antibiotics when being treated at a hospital in Guangdong Province.

It was believed this was because the child's mother had eaten meat and eggs containing antibiotics.