ST. LOUIS – Post Holdings, Brentwood, Mo., recently learned that layer hens at an Iowa-based third party supplier were infected by avian influenza.

Post Holding said the company was notified of the outbreak on April 27. The outbreak impacts the company’s Michael Foods Group, which makes breakfast foods.

The farms houses approximately 5.5 million birds which represent approximately 10 percent of the company's egg supply, the company said. Post Holdings said the company is in the process of completing an analysis of the financial impact, if any, of the outbreak.

“We are working with our suppliers and customers to mitigate the impact of this unfortunate event,” said Rob Vitale, president and CEO of Post. “I have confidence in our team to respond quickly and effectively.”

The US Department of Agriculture’s updated list of confirmed avian influenza findings showed a flock of 1.7 million chickens was infected at a commercial poultry operation in Sioux County, Iowa.