<P> With an aggressive bull, a short length of chain or rope may be left hanging loose from the ring, so when he ducks in a threatening manner, the bull will step on the chain and be deterred from attacking . This lead may also facilitate capture and control of a frisky bull . </P> <P> Bull rings are usually about 3 to 5 inches (8 to 13 cm) in diameter, depending on the size of the bull . Bull rings are commonly made from aluminium, stainless steel or copper, in the form of a pair of hinged semicircles, held closed by a small brass bolt whose head is broken off during installation . If a ring needs to be removed (for example, if the bull has grown out of it), it is cut or unscrewed . </P> <P> 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) have been available for many years; these are also usually installed by a veterinarian rather than the owner . </P> <P> Calf - weaning nose rings or nosebands provide an alternative to separating calves from their mothers during the weaning period . They have plastic spikes which are uncomfortable for the mother, causing her to reject the calf's efforts at suckling . Weaning nose rings are also available for sheep and goats . These nose rings (usually made of plastic) clip onto the nose without piercing it, and are reusable . </P>

How do you put a ring in a bull's nose