The ban will be carried out in four phases, said Dongguan Vice-Mayor Li Xiaomei at a meeting on Tuesday to address the problem of live poultry pollution.

Local authority officials will inspect pig farms that are allowed to operate before the deadline and make public their decisions by December 15.

Up to 433 pig farms in 10 Dongguan towns, rearing 100,000 pigs, have secured temporary operation passes, the Southern Metropolis Daily has reported.

The pig farms must now meet seven conditions - including being located in approved areas for pig-farming; not disrupting the lives of residents; not spoiling the appearance of the city and not polluting water resources.

Those who fail to meet the conditions will be closed down by the end of this year, Li said, adding that even those with temporary operational passes will be removed by the end of next year.