Nasal septum in bull calves be punctured for pulling a rope or nose ring at the age of

Nasal septum in bull calves is punctured for pulling a rope or nose ring at the age of 12 months.
Some nose rings are installed through a pierced hole in the nasal septum or rim of the nose and remain there, while others are temporary tools.
Bull rings are usually 8 to 13 centimetres (3 to 5 inches) in diameter, depending on the size of the bull. The ring is normally placed on the bull between 9 and 12 months of age. It is usually done by a veterinarian, who pierces the septum with a scalpel or punch.
Self-piercing rings (with sharp ends designed to be pressed through the septum and then pulled together with a screw).