Bottles of raw milk are displayed for sale at a store in Temecula, Calif., on Wednesday, May 8, 2024. Sales of raw milk appear to be on the rise, despite an outbreak of bird flu in U.S. dairy cows.

The additive, which is for sale in 68 countries around the world, has been approved for use by U.K. regulators, with several major supermarkets set to stock milk produced by cattle eating feed ...