A spokesperson for Northern Ireland Fire and Rescue reported firefighters in attendance shortly before 6.30pm on Monday.
In a Twitter message, the NIFRS spokesperson said: “NIFRS are currently attending an incident at Fleming Poultry, Ballymena Road, Ballymoney.
“We would ask that residents in the area including the Garryduff Road to stay indoors and close all windows.”
The tweet added: “We are utilising resources from a number of areas to deal with the incident.”
At least 12 fire appliances are reported to be operating at the incident.
There are no further details at present.