They also have a flap of skin on the bottom of their necks called a dewlap.
During the rut, bulls roll around in basins of urine known as wallow pits, and the dewlap waves the funky perfume around.
First, the number of nodes from ground level to attachment of the top visible dewlap leaf was counted.
British Dictionary definitions for dewlap
a loose fold of skin hanging from beneath the throat in cattle, dogs, etc
loose skin on an elderly person's throat
C14 dewlappe, from dew (probably changed by folk etymology from an earlier form of different meaning) + lap1 (from Old English læppa hanging flap), perhaps of Scandinavian origin; compare Danish doglæp