Bovine somatotropin (bST), a genetically engineered hormone for dairy cows that could increase milk yields by as much as 10 to 25 percent, is currently in the final phases of the U.S. Food and Drug Administration (FDA) approval process. Anticipating its ultimate approval economists and industry analysts have concentrated their studies on the potential impact of bST on individual farmers, as well as on the dairy industry as a whole-the supply effects. In contrast, demand aspects have been largely ignored. But they shouldn't be because consumer backlash to bST in terms of lower demand could be substantial.