The ban means that breeders in 18 départements in southwestern France aren't allowed to have any ducks or geese in their slaughterhouses or production rooms until mid August.
"My gavage room is empty," breeder Florence Lasserre told the France Info channel, referring to the room where ducks and geese are force-fed grain.
"Usually it's full here, and it feels a bit lonely now, but the main thing is that the virus doesn't return."
The virus that Lasserre refers to is the highly virulent H5N1 strain of bird flu that was identified at a chicken farm in Dordogne in November, triggering intervention by veterinary watchdogs.
H5N1 is is highly lethal to birds but does not infect humans easily, although when it does it is fatal in about 60 percent of cases, the World Health Organization (WHO) says.
The potential for infection comes when a human is in very close contact with a live bird which is sick with the disease.
While the breeders' losses of an estimated €130 million will be compensated by the ministry of agriculture, the producers won't be so lucky in the following months.
Marie Pierre Pé, spokesperson for producers' federation Cifog, said that 4,000 jobs would be affected in some way.
"This interruption to our business will cause cash flow problems, additional wage costs linked to the temporary unemployment of around 4,000 workers, and fixed costs that will have to be paid despite us not having any income," she said, reported Le Figaro newspaper.
The 18 départements that are affected correspond to over 70 percent of France's total foie gras output, meaning firms that produce foie gras could be out of pocket by €140 million, she added.
And it's not just foie gras. They'll also be losing out on sales of other duck-based staples of the French diet, such as magrets de canards and confits de canards.
Producers are expected to fork out for new biosecurity measures too, the exact details of which are yet to be announced by the government, but which are estimated to come at a cost of €220 million.
Customers of the "fatty liver" may be hit too, as the shortage could see prices shooting up.
There will be 9 million ducks fewer on the market this year, one farmer told Le Figaro, adding that the price for consumers "will have to go upwards".
The typical French person spends around €29 a year on foie gras, the paper reported.
France, which produces 75 percent of global foie gras, exported nearly 5,000 tonnes of it in 2014. Production in the Dordogne is covered by a "protected geographical indication" label - a European Union (EU) scheme to defend local skills and values from imitation.
The luxury dish has become a battleground between animals-rights campaigners and defenders of France's gourmet traditions.
Force-feeding - known as "gavage" in France - has been banned in several countries but is legal in France.