I think because bird flu is passed from waterfowl to chickens that you may not be allowed to keep a mixed flock of both chickens and ducks and still sell eggs to the public. That is my opinion. If you find otherwise let me know.
As far as I know The only test that is mandatory is the NPIP tests for Pullorum and this test is REQUIRED before you can ship eggs or birds in Interstate Commerce.
15 states require ms/mg testing..several require AI testing to import birds to them....