Crackdown Upends Slaughterhouse’s Work Force

Last November, immigration officials began a crackdown at Smithfield Foods’s giant slaughterhouse here, eventually arresting 21 illegal immigrants at the plant and rousting others from their trailers in the middle of the night.  Since then, more than 1,100 Hispanic workers have left the 5,200-employee hog-butchering plant, the world’s largest, leaving it struggling to find, train and keep replacements.