A sheep is believed to have become the world most expensive after selling for £231,000. Deveronvale Perfection, bred in Banffshire, was bought by a fellow local sheep farmer at a sale in Lanark.

But on the dairy side of the spectrum, there's an unusual milk that is the most expensive in the world -- and it doesn't come from a cow, a sheep, or a goat. This scarce and valuable product comes ...