President Donald Trump on Tuesday plans to order meat processing plants concerned about coronavirus outbreaks to stay open to protect the food supply in the United States, drawing a backlash from unions who said at-risk workers required more protection. With concerns about food shortages and supply chain disruptions, Trump is expected to sign an executive order using the Defense Production Act to mandate that the plants continue to function, a senior administration official said. … The world’s biggest meat companies, including Smithfield Foods Inc, Cargill Inc, JBS USA and Tyson Foods, have halted operations at about 20 slaughterhouses and processing plants in North America as workers fall ill, stoking global fears of a meat shortage.