The state Department of Agriculture, Trade and Consumer Protection has ended quarantines at three of the nine poultry producers hit by avian influenza earlier this year.

The affected operations are in Chippewa, Barron, and Jefferson counties. The end of the quarantine means they will be able to restock their barns and resume business, months after they were shut down and forced to destroy their flocks.

Cases of avian influenza spiked this spring, with several neighboring states also seeing a large number of outbreaks. In Wisconsin, the virus forced the destruction of more than a million birds.

There are still six sites in the state under quarantine. They are in the final stages of testing for the highly contagious flu virus before they will be allowed to reopen.

While the virus has not been seen in Wisconsin since this spring, ag officials caution it could make a return this fall when temperatures fall and wild birds begin to migrate.