More than 1400 workers from dairy producers Fonterra, Saputo, Lactalis and Peters are striking for 48 hours as they demand better pay and conditions.
The processing staff at 13 regional and metro sites started their industrial action on Wednesday.
Coles and Woolworths say there are no milk shortages at their supermarkets and the companies have no plans to introduce buying limits.
"We are continuing to work closely with our suppliers to help ensure milk is available to our customers," a Coles spokeswoman told AAP on Thursday.
Any potential impacts would be limited to Victorian stores but there were measures in place to ensure there was no significant impact to supply, a Woolworths spokeswoman said.
"We're in close contact with our Victorian milk supplier and we're working on contingency plans to minimise any potential disruption to our customers," the statement to AAP read.
Fonterra also confirmed it was continuing to collect and deliver milk from dairy farmers amid the strike action.
"We executed our business contingency plans successfully," supply chain and operations director Rob Howell said.
"Our primary focus was to ensure that all of our farmers' milk was collected and ready to turn into dairy products that our customers love."
The United Workers Union claim major dairy producers have failed to offer striking workers fair wages and conditions amid rising living costs.
Workers are also seeking paid emergency service leave so volunteer Country Fire Authority workers can address natural disasters when required.
"You can't run a dairy processing plant if all the dairy farms are burnt out," the union's national secretary Tim Kennedy said.
"Emergency service leave is one of the reasons these workers are on strike because they know how important their volunteering during emergencies is to others in their regional community."
Mr Howell said Fonterra remained focus on negotiating in good faith with its workers.
Saputo, Peters and Lactalis have been approached for comment.
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