Locals say many families rely on income from the co-operative's factories
Hundreds of jobs are under threat in Denbighshire and Bridgend after the co-operative Dairy Farmers of Britain (DFOB) went into receivership.
DFOB - which employs 2,200 across the UK - includes two sites in Wales, at Llandyrnog, Denbighshire and Bridgend.
Some farmers have not been paid for last month's milk; one is owed £15,000.
Local people say the community depends on the jobs. A union spokesman said it was "devastating" for an already struggling industry.
DFOB has 1,800 member farmers who supply more than a billion litres of milk each year and is responsible for 10% of the UK's milk production.
According to figures in October 2008, the creamery at Llandyrnog, which first opened in the 1920s, employed 160 people and had a turnover of more than £70m.
There are many families with many members of that family all relying on the income from the factory
Local Graham Carrington-Sykes
The Bridgend site, acquired in 2006, is capable of processing 200 million litres of milk each year, supplied by farms across south Wales.
In north Wales, any jobs losses in Llandyrnog would hit the area very hard, locals said.
Farmer Gareth Edwards wasa member of the co-operative and says he currently has no buyer for his milk
Resident Graham Carrington-Sykes said he hoped something could be done protect the future of the dairy.
"There are many families with many members of that family all relying on the income from the factory... the local shops, the local pubs and crucially all the farmers," he said.
Another local, Bethan James, said in some cases more than one member of a family were employed there, working opposite shifts in order to organise childcare
"I have got many friends that work within there that are couples," she added. "Yes, it would hit the village, very much so."
Eifion Huws, chair of the milk committee for the FUW, said some farmers had not receive money owed for last month's milk - a total of £15,000 in his case.
Mr Huws said other dairies would be unlikely to take on more farmers because of the availability of cheap imported milk.
Only yesterday the county was dealing with news that Indesit was to close its Bodelwyddan plant with the loss of over 300 jobs
Councillor David Thomas, Denbighshire Council
John Gorle of Union of Shop, Distributive and Allied Workers (USDAW) - which represents the majority of DFOB workers - said while it might be a struggle to find a buyer for the whole of the business, he was "very hopeful" one would be found for Llandyrnog.
"It's a well run, efficient operation with a loyal and committed workforce which even in this difficult situation I believe has a future," he added.
National Farmers' Union (NFU) Cymru President Dai Davies, a dairy farmer from Carmarthenshire, said his "number one priority" was to help members "through this difficult time".
Meanwhile, Denbighshire County Council said it would be calling for an urgent meeting with DFOB's owners and the Welsh Assembly Government's Rural Affairs Minister Elin Jones.
Councillor David Thomas, cabinet lead member for regeneration, said: "Yet again today we are having to deal with another major blow to the county's economy.
"Only yesterday the county was dealing with news that Indesit was to close its Bodelwyddan plant with the loss of over 300 jobs."
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