A sharp decline in the number of dairy heifers available to replace older cows exiting the U.S. dairy herd could limit any meaningful growth in domestic milk production during the next few years. The number of dairy replacement heifers has decreased almost 15 percent during the past six years to reach a 20-year low, according to data from the U.S. Department of Agriculture’s most recent Cattle report. While the global demand outlook for U.S. dairy products remains murky due to export market uncertainties, any potential growth opportunities may be stymied by an inability to expand U.S. milk production.