She said such an assumption is not supported by practices at the farm, where the birds roam freely and are fed by hand every eight hours. The force-feeding begins when the ducks are fully grown, about 12 weeks after they’re born. A worker inserts a 6-inch (15-centimeter) plastic tube into the duck’s beak, squirting a soft mix of corn, soybeans and water to the top of the throat. They’re fed for three weeks, then slaughtered.
Article source: https://www.huffpost.com/entry/new-york-city-foie-gras-ban_n_5dbb0eebe4b00d83f7248c55