Methods involve feeding young animals milk products containing milk-based protein, a halide and a source of hydrogen peroxide, where an active lactoperoxidase system is not present in the milk product fed to the young animal, in response to ingesting the milk product, the young animal decreases a feed to gain ratio. Milk replacers may be provided as the milk product, and the young animals may be calves. Milk replacers contain milk-derived protein, a source of hydrogen peroxide at about 50 to about 500 parts per million by weight of the rehydrated milk replacer and iodide at about 1 to about 50 parts per million by weight of the rehydrated milk replacer, where an active lactoperoxidase system is not present.
