DES MOINES, Iowa (AP) — Meatpacking plants that had to briefly close due to coronavirus outbreaks have been back up and running for weeks, but production backlogs are forcing farmers to euthanize thousands of hogs that can't be processed, drawing complaints from animal welfare advocates.

In Iowa, where nearly one-third of the nation's hogs are raised, the temporary closure of slaughterhouses led to a backup of about 600,000 pigs, state Agriculture Secretary Mike Naig said. Those plants now are operating at about 80% capacity, but that's not enough to clear the backlog, and efforts to sell dire...