The company had been forced to suspend operations at the plant when the US Food Safety and Inspection Service FSIS withdrew inspection at the plant after an infestation of cockroaches was discovered on the processing floor.

The company announced on Friday that it was due to restart operations on Saturday 11 January.

However, the company decided to temporarily suspend operations again to enhance its food safety measures.

The company said that Livingston maintenance employees will remain on the job; the remainder of plant employees will be called back when the plant resumes full operations.

“The company is exercising vigilance and choosing to dedicate additional time to ensuring its preventative plan is fully realised with the most effective technology and treatments available,” a company statement said.

“Foster Farms expects this closure to be brief, lasting several days, but does not at this time have a definitive date for resuming operations.

“No other plants are affected. Company officials said that no product, packaging or line was in any way affected. Production will be shifted temporarily to the company's two other Central Valley, California plants.

“Foster Farms shares a common goal with the USDA-FSIS of contributing to a safe food supply, as we have done since 1939. Foster Farms President Ron Foster said, "On behalf of my family, I made a commitment to making this right and we are taking every opportunity to ensure the long-term efficacy of our program at this plant. We are confident in the preventative plan and want to take the time to properly implement new measures to our satisfaction. Foster Farms is a company that strives for excellence. We will not resume operations until we are confident that we have the most stringent and effective treatment protocols in place."