Certain forms of paté are obtained by force feeding animals to provoke an organic disorder which grossly enlarges the liver from which the paté is derived. Some delicacies, requiring little preparation, may involve consumption of a portion of an animal whilst it is still alive, as in the case of monkey brain. In Geraardsbergen, east Flanders, a ritual of the town's annual Pretzel Festival is to drink glasses of wine containing live fish. Live turtles were used as a source of fresh food on board ship, only discarded when they died after days or weeks of agony. Turtles are butchered alive in modern Asia food markets and remain alive, deshelled and eviscerated, on tressels awaiting purchase. It is even possible to maintain animals alive as a constant source of supply of blood for drinking, as in some uses of cattle.