Pressure is building on the country's meat works as lamb numbers dwindle amid the oversupply of killing sheds, and the potential for a shorter killing season is looming.
New Zealand Meatworkers and Related Trades Union Otago-Southland branch secretary Gary Davis said many sheds across the country were already on six-hour days and shortened weeks.
There has been industry speculation Alliance Group's Mataura plant could be facing cuts, and that a meeting with workers had been called for this week, but chief executive Grant Cuff declined to give any details.
He said Alliance was always looking at its plant performance and capacity.
When asked about possible job cuts or shift changes, he said he had "nothing to add".
Mr Davis said both Alliance and Silver Fern Farms would now be looking closely at lamb numbers and he "would not be surprised" if they initiated shift changes.
During the past two years, the South had lost about one million lambs in the severe 2010 snowstorm and a similar number because of drought last season, which required stock to be sent north for fattening.
"These add up to significant numbers over time," Mr Davis said.
