Victoria's abattoirs and meat processing plants will have to scale back to two-thirds of production, under stringent new state government coronavirus regulations.
On Sunday, the government declared a state of disaster, imposing stage four restrictions for Melbourne and stage three for the rest of Victoria.
The abattoir restrictions will be in place for six weeks, from midnight Friday.
Meatworkers will have to wear full personal protective equipment, including gloves, gowns, masks and shields.
"We know that meatworks are a really significant challenge for us, whether it be lamb, poultry, or beef, they will move to two-thirds production, reducing their production by one third," Mr Andrews said.
There are about 56 cattle, sheep, pig and poultry abattoirs in Victoria.
Australian Meat Industry Council chief executive Patrick Hutchinson said the organisation had been lobbying tirelessly on its member's behalf to ensure that they remained an essential service in the supply of food.
"The impact of these restrictions in Victoria, AMIC believes will lead to a 30 percent reduction in supply chain throughput overall, based on discussions with our membership," Mr Hutchinson said.
"It is our opinion that this will lead to a reduction in saleable meat in the Victorian community."
Mr Andrews said abattoirs and meat processing plants would operate very differently, for the next six weeks.
"There will be some of the most stringent safety protocols that have ever been put in place, in any industrial setting," he said.
"Those workers will essentially be dressed as if they were a health worker."
Mr Andrews said staff would be working at one site only, and be temperature checked and tested.
"It is a proportionate response, to the risk that industry poses."
But given their critical role in keeping Victoria, and the nation fed, it was not possible to go below the two-third production level.
Mr Andrews said it was a less busy time for abattoirs, than in spring.
"That would be a very different set of circumstances," he said.
The government had decided to apply the stringent restrictions to all Victoria abattoirs.
"There will be COVID-Safe plans for all industries, particularly those that are at higher risk," Mr Andrews said.
"You can't have a situation where such a high risk environment is operating under two different sets of rules, in two different parts of the state, that will only contribute to further outbreaks," he said.
Thomas Elder Markets analyst Matt Dalgleish said a one-third reduction would be of a similar magnitude to the fall in production in the US, in April, although the impact there was more widespread.
"US cattle sector dropped production by about that amount in April and resulted in a 20 per cent fall in finished cattle prices and a 100pc rise in beef cut out prices at the wholesale level," Mr Dalgleish said.
"But I don't think it will be extreme as that for Victoria, in terms of price impact, as there are still abattoirs operating in other states that can pick up the slack.
"There will be some price effect."
He said he felt is was neccessary, to get on top of the spread of coronavirus.
"At least it's during winter," he said.
And the Australasian Meat Industries Employees Union has confirmed JBS is shipping cattle, to its Longford plant, Tasmania, for processing.
The AMIEU's Tasmanian state secretary Andrew Foden said JBS had started bringing cattle to Longford, when its Brooklyn plant closed.
JBS is also moving Victorian cattle to Scone, NSW, and SA for processing.
He said the Longford plant was now operating five days a week, although the company had planned to cut back to four days, in mid-August.
"The Victorian cattle have kept the five day trade going, here in Tasmania," Mr Foden said
"The workers are also going through an extreme amount of overtime, at the moment,".
"We are lucky we have that 200 kilometres of water, it's kept us coronavirus safe."
JBS and the Australian Meat Industry Council have been contacted for comment.