Cranswick Country Foods recommenced processing at its pig factory in Cullybackey, Co Antrim, on Friday morning.
Production at the site was suspended on Saturday 22 August after coronavirus cases were identified among staff.
All workers were required to self-isolate for 10 or 14 days, depending on the result of COVID-19 tests.
“It is positive news that Cranswick has reopened and it will be well received among our pig producers,” said Ulster Farmers’ Union (UFU) president Victor Chestnutt.
The two-week closure of Cranswick’s facility has led to a build-up of finished pigs on local farms.
Some of these pigs have been redirected for slaughter to the two other pork processing sites in NI, namely Karro in Cookstown and William Grant & Co in Derry.
“We want to thank the processors for working together, helping us to get to this stage. We encourage them to continue working together in such an effective manner, maximising the throughput of pigs and alleviating any backlog which may have been starting to occur on farms,” said Chestnutt.
The UFU president also thanked government ministers and civil servants for being involved in talks to manage the effect of the factory closure.
“The safety of everyone remained a priority while we worked to ensure that the pig trade was not disrupted and farmers were not left struggling to house pigs for lengthier periods than initially planned,” he said.