Dehorning is used to keep cattle from hurting one another, to reduce the risk to workers, simplify transportation, free up trough space, and to give both dominant and subordinate animals an equal chance to feed.

According to the Canadian Beef Quality Audit, the Canadian cattle industry loses millions of dollars annually due to carcass bruising – almost twice as much meat must be cut from the carcasses of cattle with horns than those without.

In Australia, losses due to carcass bruising amounts to approximately AU$30 million, or AU$4 per animal slaughtered per year. Research shows that most of the bruising is caused by horns.

dehorning
When using a hot iron, it must be applied long enough to leave a clearly visible light brown circle.

There are several ways to dehorn cattle, but breeding polled cattle is the best in terms of animal welfare. There are at least five markers that can ensure a 90% heritability of the trait and producers can select sires that carry the polled gene to incorporate polled calves into their herds. This gene is dominant and needs to be present in only one parent. Polled genetics are more common in beef cattle than dairy breeds.

Methods of safe dehorning

Dr Danie Odendaal, a veterinary herd health consultant and director of Veterinarian Network, says there are two popular methods of dehorning in South Africa: using a hot iron, or applying a paste that eats away the cells of the horn, preventing them from growing.

Calves are born with small protrusions called buds, from which their horns will grow. Studies show that the younger the calf, the less pain they feel and the quicker their recovery. The horns attach to the skull when the animal is around two months of age, making it more difficult and painful to remove. Trying to remove the horns once this has occurred, will likely leave a hole in the animal’s sinus cavity.

When using paste, it must be applied from the first week after birth. The paste, which contains caustic soda, must be applied to the horn buds. This requires careful management because it must be done once a week during the calving season. Dr Odendaal says the person applying the paste should wear a protective shield over his finger and the paste must be thoroughly rubbed around the horn bud.

dehorning
Paste can be used to dehorn calves from the first week after birth. Take a disposable glove, cut off a
finger and place it over your finger to prevent any burns. Rub the paste into the skin around the horn bud to prevent the horn from growing back.

The dehorning iron has a round, hollow head that fits over the horn bud. The iron is available in different sizes and it is essential to choose an iron that will cover the entire bud. The iron, which must be red hot, burns and destroys the horn-producing skin at its base and the bud will drop off once the wound has healed. The iron must be applied using a rotary action.

Risk of complications

Care should be taken before dehorning older and mature animals, as complications can occur. The main problem is that the sinus cavities, which are open until the wound has healed, can become inflamed. An alternative is to cut off the sharp ends of the horn. However, this is not a permanent solution as the horns will grow back.

The key to successful dehorning, regardless of the method used, is to destroy a complete ring of hair (approximately 1cm wide) around the base of the horn. If it is too narrow, the horn might grow back; if it is too wide, it will cause a larger, more painful wound.

For more information, contact Dr Danie Odendaal on 082 454 0532 or veeartsnetwerk@gmail.com.