Bird flu was confirmed at an egg farm with 4.2 million hens in Sioux County in northwestern Iowa, the first outbreak in the state this year, said agriculture officials. The Sioux County farm is one of the largest egg farms in Iowa, the No. 1 egg-producing state.
There are roughly 378 million egg-laying hens in the country, according to the USDA. As a matter of course, animal health officials mandate the culling of all birds in an infected flock to prevent the virus from spreading. Left alone, the highly pathogenic avian influenza virus would wipe out a flock quickly.
Outbreaks of bird flu began in the United States in February 2022 and have occurred in almost every state. The H5N1 bird flu virus jumped to dairy cattle in late 2023 or early this year.