“California and New York were our biggest markets, so this is devastating,” said Mr. Saravia, adding that his farm has lost $50,000 a week in revenue from the loss of the California market. “It’s going to make it difficult to stay afloat.”

Ms. Rivera said that changes were made to the original bill’s language to help upstate farms.

The ban will not take effect until three years after its passage, giving the farms a chance to adjust their business models, she said. The maximum fine for violating the ban was increased to $2,000 per violation from $1,000, but a proposed criminal penalty of up to a year in jail was eliminated.

Ms. Rivera rejected the notion that the ban would put the upstate farms out of business.

“These farms produce dozens of other products and gavage is aggressively cruel,” Ms. Rivera said. “There is an exotic animal ban in New York City and people still go to the circus.”

More than half the City Council — 30 members — signed on to sponsor the foie gras legislation, which was part of a package of anti-animal cruelty legislation that advocates said was among the most significant to be passed in New York City in years. In the end 42 members voted in favor of the ban.

Other legislation passed in the package will prevent horse carriages from working on humid days (measured using the equine heat index, a measure of temperature and relative humidity), create a mayor’s office of animal welfare and prohibit the capture and transfer of wild birds like pigeons. New York City’s ubiquitous birds are sometimes trapped and transported out of state to be used as targets in game shooting.