Historically, farmers have exclusively used male ducks to produce the controversial French delicacy because the livers of females are much smaller and harder to work with.
But after some 16 million birds were slaughtered between Nov 2021 and June 2022, farmers said they were left with no choice but to use female birds to make up for the shortfall.
As many as 80 per cent of ducks being used to make the delicacy are now female, he said.
“It was double or nothing,” Benjamin Constant, president of the foie gras marketing board for the Gers department, told French broadcaster BFMTV.
“Either we just sat and waited - which is not in our nature - or we try to offer a product that respects our consumer,” he said.
Mr Constant went on to insist it would only be a temporary measure.
While most duck livers have veins that are removed to create a smoother texture, the veins on female livers are much bigger and harder to remove.
The shortage created by the bird flu epidemic also means that foie gras prices have shot up by more than €10 (£8.62) a kilo in the last month alone.
According to France’s agriculture authority, which monitors food prices, the average price of foie gras rose from €47 (£40.51) per kilo on Nov 18 to €57 (£49.13) a kilo on Dec 2.
'Torture in a tin'
Animal rights groups, meanwhile, have long denounced the force-feeding methods used to make foie gras as unnecessary cruelty.
Often described as "torture in a tin", King Charles officially banned the French delicacy from all royal residences last month.
In a letter sent to the animal rights group People for the Ethical Treatment of Animals, Buckingham Palace confirmed that no royal household had bought or served foie gras.
“There are no plans for this policy to change,” said the letter.
France, however, remains the world’s largest foie gras producer and consumer.
Some 30 million ducks are typically raised every year to make the product, though some French cities have banned it from official functions.