NANNING, Dec. 10 -- China's livestock industry, vital to the nation's food security, has become a growing pollution and public health headache in some rural areas.

In Santang Township in south China's Guangxi Zhuang Autonomous Region, farmers simply dump the carcasses of their animals without any treatment, according to Liu, a local villager.

"If the number of dead animals is big, we usually dump the carcasses in remote places away from rivers to prevent disease," Liu said, adding that there are no decontamination facilities in his village.

The Animal Epidemic Prevention Law says that animals which die of disease on farms must be burned at appointed treatment stations. However,in many places such facilities are outmoded and unfit for purpose.

PIGS MAY FLOAT

Fang Huansen, head of animal health supervision in Ningming County of Guangxi, said that carcasses thrown into ponds or rivers could seriously pollute the water, making it highly injurious if consumed.

Carcasses are often dumped to reservoirs of disease and could cause epidemics or transmit infections to both animals and humans.

He Ruogang, professor of animal science and technology at Guangxi University, believes the problem is not just illegal dumping, but lack of supervision means diseased meat often makes it onto the market.

"Profits on meat are high, as are the costs of treating fallen stock, so some greedy farmers sell the carcasses at very low prices to processors who sell it on the market," He said.

Guangxi is only an snapshot of a bigger picture. As livestock breeding goes industrial, it brings serious environmental worries.

In March, the rotting bodies of nearly 6,000 pigs were found in a river that provides 22 percent of Shanghai's tap water, causing panic in China and international scorn.

Despite authorities' protestations that the river was not contaminated and Shanghai's tap water was safe, laboratory tests found porcine circovirus in one water sample. The virus is spread among pigs though not transmissible to human beings.

The source of the dead pigs remained a mystery until a hog farm in Jiaxing City in neighboring Zhejiang Province, confessed on March 13. Jiaxing authorities said 70,000 pigs had died this year from climate conditions and changes to farming techniques.

On the same day, a court in Wenling City, also in Zhejiang, sentenced 46 people to prison terms ranging from six months to six and a half years for processing and selling pork from diseased pigs from 2010 to 2012. Wenling's pork safety campaign, which began in April last year, has meant the seizure of more than 6 tonnes of pork products that tested positive for various viruses.

MOUNTAINS AND RIVERS OF WASTE

Another source of pollution is animal waste, particularly on hog farms.

Pig excrement and urine cause pollution due to farmers' indifference to environmental protection and insufficient spending on waste management.

The problem is so serious that some villages have become known as "pig shit villages," according to Fang.

Santang Township boasts more than a decade of pig raising and farmers simply pour their waste into a local pond, where villagers once washed clothes. The water has turned black and the fish have all died. The air has a terrible smell.

In Bobai, the region's biggest pig town, villagers dump untreated waste in their yards or on their crops, polluting water, soil and air. It is the same in Shanggao Township in east China's Jiangxi Province.

The township, population 300,000, is home to a huge pork industry, with an average of 2.7 pigs for each person. Over 2,000 tonnes of solid waste and up to 5,000 tonnes of waste liquid are produced on a daily basis.

Biogas digesters cannot cope and a large amount of effluent is discharged directly without treatment, polluting the air and groundwater.

And it is not just pigs, poultry and cattle industries are every bit as bad, according to Fang.

Jiang Yongqiang, in charge of animal husbandry in Guangxi's Luchuan Township, believes that the key to tackling pollution lies in farmers' awareness of the environment.

"It is necessary to promote environmental protection via the media and training to let them know that the pollution will cause them losses, or even damage to themselves," Jiang said.

He Ruogang said that government at various levels should allocate more funds to treatment facilities and encourage farmers to recycle the waste into clean energy.

Li Liping, a lawyer with the Beijing Sun God Law Office, said that the law needs to be improved.

"Environmental problems in stock raising involve departments like health, animal husbandry, inspection and quarantine so it will take all of these departments to deal with the problem," Li said.

Those responsible for major outbreaks of disease should be held accountable, she added.