During the takeoff run, the aircraft's nose landing gear collided with a pig that had strayed onto the runway. The nose landing gear collapsed, causing both propellers to strike the ground. The aerodrome was surrounded by an electric fence designed to prevent the entry of animals. This had been breached once before, and the fence had been repaired. An inspection by the council aerodrome inspector did not reveal where the pig had gained entry. The inspector now conducts daily inspections of the aerodrome area before the arrival of the regular public transport flight, and the electric fence power unit has been upgraded.