The action called by the Government this week also includes turkeys, ducks and geese.
Bird owners across the country are being forced to keep their animals inside and follow strict biohazard measures.
It comes after some 19 cases of the disease were recorded and amid concerns over wild birds migrating to the UK from mainland Europe
One of the county's main egg suppliers, the family-run L J Fairburn & Son Alford, commented: "The welfare of our hens is paramount and forms the foundations of our business.
"We strictly adhere to industry guidelines on the issue of Avian Influenza including keeping birds inside when the risk level increases as it did this week.
"Like all other bird keepers in the UK, we have moved our hens into their houses, and will continue to maintain high levels of biosecurity on all our farms."