Americans could start to see shortages of pork, chicken and beef on grocery shelves as soon as May as major packing plants swept by the coronavirus remain shuttered and the nation’s massive stockpiles of frozen meat begin to dwindle.

Any empty shelves to date have been the result of bumps in the supply chain, with stores being unable to restock as quickly as customers are buying. But bacon, pork chops and ham could be the first to face actual shortages: The amount of frozen pork in storage nationwide — more than 621 million pounds — dropped 4 percent from March to April, the USDA reported this week. Slaughter rates are down 25 percent, and 400,000 animals are backed up in slaughterhouses.

And with meat plants of all kinds operating at 60 percent of capacity, shortages loom for beef and poultry as well. That could also lead to higher prices and a financial squeeze for farmers, who are collecting less per animal slaughtered.