Many believe only male cattle, or bulls, have horns. However, female cows, including heifers (young females that have not yet given birth), can grow horns. The presence or absence of horns in cattle is primarily determined by their genetic makeup and breed, rather than their gender alone.
The Biology of Horn Growth
Horns are permanent structures that begin to grow shortly after a calf’s birth and continue to develop throughout the animal’s life. These projections consist of two main parts: a bony core that is an extension of the frontal bone of the skull, and an outer covering made of keratin. Keratin is the same protein found in human hair and fingernails, providing a durable and protective sheath. Horn growth originates from specialized cells located at the horn bud, which is present on the calf’s head from birth. Initially, this horn bud is free-floating in the skin, but within approximately two to three months, it attaches to the skull. The biological mechanism for horn development exists in both male and female cattle, provided they inherit the genes for horn growth.
Horned Versus Polled Cattle
The presence or absence of horns in cattle is largely governed by a specific gene, known as the “polled” gene. The polled trait is dominant, meaning an animal needs only one copy of the polled gene from either parent to be hornless. Conversely, the horned gene is recessive, requiring two copies for horns to develop. Many cattle breeds are naturally polled, such as Angus and some varieties of Hereford. Other breeds are known for their prominent horns, including the Texas Longhorn, Highland cattle, and Ankole-Watusi, where both sexes commonly grow horns. Selective breeding practices have allowed for the development of polled strains within many traditionally horned breeds, offering farmers the choice between horned and hornless animals.
Managing Horns on Farms
In commercial farming, horns are often removed from cattle through procedures like dehorning or disbudding. This practice is undertaken for several practical reasons, primarily focusing on safety for both animals and human handlers. Horned cattle can inflict injuries on other animals within the herd, leading to bruising or more severe damage, and they can also pose a risk to farm workers. Removing horns also offers economic benefits by reducing carcass damage from bruising, requiring less space during transport, and facilitating easier handling and management in confined areas like feedlots or milking parlors. Disbudding, which involves destroying the horn-producing cells of the horn bud, is typically performed when calves are very young, often before they are eight weeks old. Common techniques include using a hot iron or caustic paste to prevent horn growth.