Horns are not shed annually. They continue to grow through the year. Cattle and goats have horns. The deer family's bony structures are antlers because they are shed annually. Deer do not always grow the same size rack each year.
Growth depends on nutrition and heredity.
Antlers can also be found on female deer. Normally the doe has spikes that remain in velvet. The spiked doe remains fertile and can produce young. This occurs in one to every 20 thousand deer. In the Maryland deer kill, only two or three antlered doe are reported each year.