The horns of bighorn sheep have an interesting roll in their biology. The males have larger and more curved horns than the females. In fact, the males' horns can weigh as much as 30 pounds, which is the same weight as all the other bones in his body combined. They can grow to be three feet long and have a one-foot circumference at the base.
Males grow such huge horns for at least one obvious reason. They use them to fight for social dominance and to be the leader of a herd that only has room for a single ram. Males run at each other at speeds sometimes reaching 30 miles per hour, creating a crashing bang that can be heard as far as a mile away. Because they dish out, and take, such a significant pounding, males have particular adaptations in their anatomy including large horn cores, enlarged cornual and frontal sinuses, and internal bony septa that allow them to absorb much of the impact of the clash.
But there's another purpose to the famous horns of these animals. Both males and females use them for eating. Bighorn sheep are found in arid locations where some of their food comes in the form of cacti. Both males and females use their horns to remove the spines and break open cacti so they can feast.