The plans are to take ten years to complete and will see a production increase from 140,000 tonnes per week to 250,000 tonnes.
Specialist concrete panels are being installed by Whites Concrete who have made the panels with numerous cut outs for pipes and doors.
Steve McLaughlin, construction manager at GA Pet Food Partners, said: “The pre-cast panels from Whites Concrete have saved huge amounts of time on our building programme.
“With such specific requirements for each panel on such a big scale, we’ve had to work very closely together to find the best, most cost-effective solutions to what continues to be a major logistical challenge.”
He added: “From day one, Whites Concrete have worked with meticulous attention to detail so that the panels are always of top quality and ready to fit in with our schedule.
“They have gone out of their way to provide us with the detail we required for such a huge number of individual panels and continue to play a very important part in the development of this major facility.”