Victorian dairy farmers face uncertainty as to whether their milk will be picked up, as processors are hit with a wave of industrial action.
At the same time, more than 150 Saputo tanker drivers, who supply sites in Gippsland are also half-way through a 48 hour strike.
Dairy Farmers Victoria president Mark Billing, Colac, said many farmers were facing uncertainty as to whether or not their milk would be collected, or if it would have to be dumped.
He said most farmers would be able to store milk for a short time.
"Most vat systems are set up to hold milk for 48 hours but the problem is that we are in the peak of the season, so most farms would be pretty close to capacity," Mr Billing said.
"The feedback I have had is that the concern is about the unknown - until the tanker driver is in the gate, they don't know if they will have a pick up, or not.
"The processors are doing their best but what I am hearing from farmers is that there is still a fair level of not knowing what's going on."
There were Environment Protection Agency rules around dumping milk, he said.
"One of the big problems is putting too much milk into our effluent pond systems, because it stops them working - environmentally, milk is terrible for them," he said.
"The fat in the milk de-oxygenates the water."
In Gippsland, several Saputo suppliers said milk had still been picked up, even after the 3am deadline had passed.
Paul Shearer, Loch, a Saputo supplier, said he hoped he would not have to dump milk on paddocks, even if it was diluted according to Agriculture Victoria directions.
"We have no hope of doing that, because our pastures are saturated as it is," Mr Shearer said.
"We seem to be the one part of the country, almost, that is complaining about the rain."
There were also problems with putting milk into effluent ponds, which were "stretched to the max."
Winslow's Bernie Free said he supplied Bulla, but Saputo picked up his milk.
He said he hadn't any indication yet, as to whether he would be affected or not, as his milk was picked up early yesterday.
In separate industrial action, workers at Fonterra's Cobden, Darnum and Stanhope factories downed tools from this morning.
A Fonterra spokesperson said it was hoped dairy farmers would not be directly affected.
"For the 48-hours of the industrial action, we expect that we will be able to continue milk collection," a spokeswoman said.
"We will be working closely with our farmers to keep them updated if the situation were to change."
The company had also "executed its business contingency plan," which meant while processing would pause, during the industrial action.
"However, we have worked out with our customers to provide good stocks of fresh milk in advance," the spokesperson said.
"We also have good inventory levels of butter and cheese to enable supply to continue based on current demand levels."
Lactalis' Longwarry site has been affected, with all 22 workers walking off the job.
Lactalis' National Milk Supply manager Paul Lorimer said the company had been in contact with its supply base.
There had been no impact on the company's ability to collect milk.
"We will continue to liaise with our farmers as the situation develops," Mr Lorimer said.
Saputo, the hardest hit of the companies, not only has striking drivers, but workers also taking action at its Allansford, Leongatha, Rochester, Kiewa, Cobram and Maffra sites.
Saputo's Milk Supply and Field Services general manager Craig McRae sought to reassure farmers the company was seeking alternate arrangements for milk collection.
Peters Ice Cream, Mulgrave, also has workers on strike.
United Workers Union National secretary Tim Kennedy said the strike action came about because the dairy companies had refused to offer fair wages and improve working conditions, amid rising living costs.
Transport Workers Union assistant branch secretary Mem Suleyman said Saputo turned over multi-billions of dollars in revenue but had "declared war" on regional jobs.
"Saputo have dragged out negotiations, they are not recognising years of loyal and dedicated service to the company by truck drivers, who did the right thing during COVID," he said.
"Now these drivers are seeking important job security, for their future."
Mr Suleyman said Saputo sat at the top of the supply chain, with no accountability.
"They are getting away with treating this loyal workforce in a very poor manner," Mr Suleyman said.
He said the TWU action was not connected to the strikes at the processing plants and unlikely to spread to other companies.
Victorian Farmers Federation president Emma Germano said the organisation hoped the industrial action was settled as soon as possible.
"We need to have a wider conversation into the future of our pivotal supply chains," she said.
""It's a balancing act, with farmers, processors, workers and the consumer all competing for a fair price that allows for a sustainable and viable dairy industry.
""Broadly speaking, we need to talk about how standover tactics have a different impact of fresh produce."
The issue was more acute, because of the loss spoilage had much wider economic and environmental outcomes, she said.
"The issue is more acute because the loss and spoilage has much wider economic and environmental outcomes."