A court in the western town of Lons-le-Saunier in the Jura region ruled that the Pelizzari group had committed an "inexcusable error" by failing to protect Serge Personeni from a work hazard.
The amount to be paid to the 59-year-old Personeni, who worked there from September 2001 until February 2008, will be decided later after he is inspected by a doctor.
Personeni was in charge of feeding and looking after nearly 4,000 pigs.
During a hearing in June, the court said Personeni was made to "work in conditions incompatible with human dignity.