Chicago—JBS USA on Monday halted production at a Nebraska beef plant that slaughters about 5% of U.S. cattle due to a fire, but said the company expects to resume operations on Tuesday. The temporary closure highlighted concerns among U.S. lawmakers and ranchers that the United States is vulnerable to supply disruptions because a handful of meatpacking companies dominate the sector and rely on large plants to produce food. The country has suffered a series of beef supply shocks over the past two years as large plants closed due to the COVID-19 pandemic, a cyberattack that crippled JBS’s operations, and another fire that shut a Tyson Foods Inc plant in Kansas for months. The JBS fire in Grand Island, Nebraska, did not impact the plant’s “primary production areas,” spokesperson Nikki Richardson said. The company, a subsidiary of Brazilian firm JBS SA, expects to resume operations on Tuesday pending an ongoing assessment …