Widespread congestion at many of the country’s key ports is posing a threat to the recent momentum of ag exports, especially shipments of value-added products, such as pork, beef and other meats, an American Farm Bureau Federation (AFBF) economist said last week.

“It’s becoming a big issue for a number of ag products, especially those exports from the ports on the East and West Coasts,” said AFBF’s Daniel Munch, who authored a recent analysis on the port congestion problem. “Those are the ports that handle a lot of our protein products which are in high demand in...