Although “dehorning” is the term generally applied to horn removal in cattle of all ages, a distinction can be made based on the stage of horn growth.
Disbudding involves the removal of horn-producing cells in calves less than two months of age. At this stage, horn buds are still free-floating and not yet attached to the frontal bone of the skull.
Disbudding by caustic paste or hot-iron destroys horn-producing cells in the horn bud. Horn buds can also be physically excised using a knife or tube/cup/spoon.
Disbudding is the preferred method of horn removal by the American Veterinary Medical Association, which also recommends the procedure be performed at the earliest age practicable.
Dehorning involves cutting out horns and horn-producing tissue after they have formed from the horn bud and attached to the skull. This occurs when the calf is around two months of age.
As horns grow, part of the frontal sinus extends into the base of the horn. When the horn is removed at this stage, the sinus is exposed and increases the risk of infection. Horns in older calves usually have a large blood supply. Coagulants, clamps or tourniquets should be used to control bleeding, and insect control should be used to prevent flies from laying eggs in the exposed sinuses.
Common mechanical dehorning methods include the use of a knife, tube/cup/spoon, Barnes dehorner, keystone (“guillotine”) dehorner, obstetrical wire or hand saw.