The latest US Department of Agriculture data shows bird flu has infected at least 80 dairy herds across ten states. There are growing concerns about rising cow mortalities from the virus and the risk of farmers culling cows to stop the spread. This could ignite economic stress across the farm belt and unleash a supply shock. Reuters spoke with a USDA spokesperson who was aware of H5N1 virus-related deaths among cow herds but said that most cows recovered.