Cows, along with all other members of the Bovidae family, do not shed their horns naturally. True horns are permanent anatomical structures that remain attached to the animal for its entire life. This permanence is due to the horn’s biological composition and its intimate connection to the skull, as they are bony extensions covered by a hard, protective sheath.
The Permanent Structure of Bovine Horns
Bovine horns are permanent fixtures due to their complex, two-part structure. The interior is a central, conical core of live bone, known as the os cornu, which is fused directly to the frontal bone of the skull. This bony core is a direct extension of the animal’s skeletal system.
The bony core is covered by a tough, dense outer sheath made of keratin, the same fibrous protein found in human fingernails and cattle hooves. The horn grows continuously from its base throughout the animal’s life, as new keratin is produced at the junction between the skin and the bony core.
The horn’s anatomy includes blood vessels and nerves that extend into the bony core, especially near the base. Because it is living tissue, removal in mature animals involves cutting into sensitive, innervated bone. In calves older than about six months, the core becomes hollow and connects to the frontal sinuses of the skull, making the structure an integrated part of the head.
Why Horns Are Not Shed: The Distinction from Antlers
The common question about shedding horns often stems from confusion between true horns and antlers, which belong to different animal families. Horns, found on cattle, sheep, and goats, are generally unbranched and present on both sexes.
Antlers, found on members of the deer family (Cervidae), are fundamentally different structures. They are composed entirely of bone, lack a keratin sheath, and grow from bony supporting structures called pedicels. Antlers are temporary secondary sex characteristics that are shed and regrown annually.
During the growth phase, antlers are covered in a soft, vascular skin called “velvet,” which supplies nutrients to the developing bone. Once fully grown, the velvet is shed, and the solid bone structure is discarded yearly, typically after the breeding season. Since horns contain a permanent, living bone core and a continuously growing keratin sheath, they lack the biological mechanism necessary for annual shedding.
Managing Horns in Modern Agriculture
Because bovine horns are permanent and can become quite large, they present management challenges in high-density agricultural settings. Fully grown horns can be dangerous, posing a risk of injury to other animals and human handlers. They can also damage farm infrastructure, such as feeding equipment and stalls.
To mitigate these risks, livestock producers use practices known as disbudding and dehorning. Disbudding is the preferred, less invasive method, performed on young calves, typically before they are eight weeks old. This procedure involves destroying the horn-producing cells before the bud attaches to the skull, often using hot irons or caustic paste to cauterize the tissue.
Dehorning is the removal of the horn after it has grown and fused to the skull, usually in older animals. Since this procedure involves cutting into the living bone of the os cornu, it is far more invasive and causes greater stress and trauma to the animal. Due to the complexity and risk of exposing the frontal sinus, dehorning in older cattle is considered a surgical procedure. Many producers are also selecting for polled genetics, meaning the animals are naturally born without horns, to eliminate the need for removal entirely.