The Driffield facilities were bought by Westland when they took over Cranswick Pet Products in April 2012.
They are the only bird feed company to have achieved the BRC rating, which includes 10 requirements related to production, packaging, storage and distribution.
Westland products produced at the Driffield facility include Nature’s Feast, Peckish and specialist bird brand Bucktons, plusown label products.
Marketing manager Rachael Dickinson said: "All of the Westland sites have achieved incredibly high standards in quality and at Driffield we have facilities which are second to none in both the products we produce and also the way we produce them.
"The continued hard work and dedication of the staff at Driffield has certainly paid off and it is due to them that we have received this rating once again."
Meanwhile. Westland has launched its 2012/13 media campaign and Peckish TV advert which will be shown 7th – 13 January, 23rd – 26 January and 30 January – 2 February.