After new tests confirmed that swine that ate feed containing melamine and related compounds is safe for human consumption, USDA says up to 56,000 swine that have been quarantined are OK for processing.
An updated FDA and USDA risk assessment found that a healthy adult weighing 132 pounds would have to eat over 800 pounds of melamine-contaminated food in one day in order to reach an unhealthy level of melamine.
The risk assessment found that melamine does not accumulate in swine, as the kidneys filter it into the animal's urine.
About 80,000 birds are still being held in Indiana pending the development of a test for detecting melamine in poultry, expected later this week.
The agencies are also looking into potential melamine contamination of fish feed. Two U.S. commercial fish farms are confirmed to have received the feed, FDA says, and fish at those farms are being put on hold pending further tests.