Staff at a North Island freezing works had their pay cut for the official two-minute silence to remember the 29 miners killed in the Pike River mine.

Staff at the Silver Fern Farms Te Aroha plant lost two cattle each from their daily quota - the equivalent of between 98c and $1.60 for each worker - after downing tools.

The silence was requested by Prime Minister John Key and observed by thousands of New Zealand workers. It marked the start of the official memorial service in Greymouth on December 2.

The pay cut has angered some of the workers, some of whom have since lost their jobs because of a fire at the plant on December 4.

"It's bloody rough, that's how bloody miserable they are," said one, who did not want to be named.

"They wrote it on the board that we would be stopping at 2pm to pay our respects. The chain stopped. We didn't expect to be docked, though."

Staff are paid for each beast they process, and have a daily quota of 280 cattle.

It takes about 63 seconds to skin, gut and bone an animal.

Depending on their experience, workers are paid between 49c and 80c for each beast processed.

The worker said the loss of pay was a "kick to the teeth".

"Two cattle, 49 cents each, that's less than $1. What's a dollar to those mongrels."

Silver Fern Farms chief executive Keith Cooper said all workers were encouraged to observe the two-minute silence.

He said the local branch of the Meat Workers Union approached Silver Fern Farms in support of observing the memorial silence.

"As the meat workers are remunerated on the basis of throughput, Silver Fern Farms offered the union the opportunity for workers to process the missed two animals at the end of day as overtime.

"However the union declined the offer as a gesture of solidarity with Silver Fern Farms as an employer and in the spirit of comradeship with the West Coast workers."

When asked why Silver Fern Farms didn't just pay the workers for the two cattle, a spokeswoman for Mr Cooper said it "just wasn't an issue at the time".

About 170 workers were thought to be affected.

Union president Mike Nahu said the local union representative declined the overtime offer because the union did not want their tribute to the miners to be based on money.

He said workers had a clause in their contract saying they could have extra time at the end of a shift to process any remaining beasts.

"We chose not to make up the loss. It wasn't about the money, it was about respect. They could have very well made it up, but that wasn't the issue."

He could not say if the local union representative explained the decision to all workers before the stoppage.

He said no one had approached the union to complain, but accepted some workers might not be happy with the decision to forgo the remaining beasts.

Engineering, Printing and Manufacturing Union president Andrew Little said he accepted meat workers were paid on a per-beast processed basis, but thought the company should have paid the workers.

"That just makes me absolutely incensed. That's absolutely unforgivable on the part of the employer to do that," he said.

"If Silver Fern Farms doesn't understand that workers share a bond of solidarity and they are going to punish them for it, that reflects really poorly on Silver Fern Farms. It's an absolute disgrace. It makes me embarrassed. They need a big slap."

The December 4 fire at the freezing works started after sparks from a contractor's saw smouldered in a wall panel, and destroyed three-quarters of the complex.

Another Silver Fern worker said yesterday that the loss of pay was raised at a meeting after the fire.

"There were quite a few people pissed off about it. It was brought up in the meeting. They were asking if they were going to get paid.

"They didn't know they were not going to get paid for it."

A third man said staff had been told not to speak to the media.

Council of Trade Unions president Helen Kelly said the situation was extraordinary.

"Given especially that a few days later the plant burned down and left them in such a vulnerable position, you might have thought that the company would have a re-think," she said.

"I don't think you'll find another worker in New Zealand who had their pay docked for taking two minutes' silence. It's an extreme lack of empathy and generosity by the company."

About 300 workers were left jobless by the fire but many have found work at other plants around the country.

280 Number of cattle processed each day by a "low grade" worker.

49 cents The amount paid to a low grader for each beast processed.

80 cents The amount paid to a high grader.

63 seconds Average time to process a beast.

2 Number of beasts each worker missed because of 2 minutes' silence.