About 100 workers at South Australia's Port Wakefield abattoir are without work, after a decision by parent company JBS to move from two shifts to a single day-shift operation.
In a statement obtained by the ABC, JBS said it needed to "align operations with supply and market conditions", partly due to the drought and an increase in the price of feed.
JBS said the decision to scale down production at the pork processing facility run by Primo came at a time of high pig prices, known as live pork prices, compounded by historically high grain costs.
As a result, 36 full-time workers and 66 labour hire workers will lose their jobs.
The Australasian Meat Industry Employees Union criticised how the company was handling the situation.
"They don't actually tell us exactly how many people they're putting off or who they're going to be, said Graham Smith, the union's federal secretary.
"They're actually not telling us very much at all."
The union and South Australia's pork association disputed that pig prices were high.
Pork SA chairman Mark Mclean said that current prices were very close to the historical average.
"The pork prices at the moment are recovering after some of the worst prices in the past two years, probably for the previous 30 years," Mr Mclean said.
"They're certainly not at high prices from a producer's standpoint."
JBS declined to respond to the ABC's request for a comment.
However, its statement said the company would work with displaced full-time workers through redundancy arrangements and provide professional support to workers "through this difficult time."
