Dehorning Methods

Table of Contents

1. Polled Bulls
2. Chemical Dehorning
3. Rechargeable Electric Dehorner (Buddex)
4. Hot Iron Method
5. Dehorning Spoon or Tube
6. Gouge or Barnes-Type Dehorner
7. Blocking the Nerve to the Horn

The choices of dehorning techniques range from genetic to surgical. The risks to the calf and the operator vary with the technique. Many producers choose to dehorn new-born calves because the techniques are easier for the operator, less stressful on the calves and demonstrate concern for the animal welfare. Here are the common dehorning methods.

Polled Bulls

Horned or polled cows mated to a naturally polled bull (Angus) will give birth to polled calves. However, some non-naturally polled bulls carry the gene for horns and will not breed true for the polled trait.

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Chemical Dehorning

Caustic chemicals will prevent the growth of horns when properly applied to the horn buds of new-born calves. The chemicals are available as sticks and pastes. To protect yourself, wear gloves when applying the chemicals. To protect the calf, avoid application near its eyes. Do not use caustics in rainy weather.

Technique

1. Push the hair back from the horn bud and apply a thin layer of caustic over the horn bud. The bud will be about the size of a 5-cent coin on a one-week-old calf.

2. Return the hair to its normal position.

3. Protect the calf and the cow from accidental caustic burns. One method is to place a small patch of duct tape on the hair over each horn bud. The duct tape usually falls off in 1 or 2 days.

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Rechargeable Electric Dehorner (Buddex)

In this method, an extremely hot metal wire destroys the blood supply to the horn-producing skin at the base of the horn bud. This is a convenient method of dehorning calves up to 4 weeks of age.

Technique

1. Follow the directions that come with the dehorner.

2. Keep the unit at a right angle to the head.

3. Check that the horn-producing skin has been cut completely through all the way around the base of the horn bud.

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Hot Iron Method

Both the 120 volt electric and the gas-fired irons will destroy the horn producing skin at the base of the horn. This technique works well for calves up to 12 weeks old. However, the technique requires good restraint of the calf. Except in very young calves, blocking the nerve to the horn is recommended. There are several sizes of dehorning irons. The proper size is one where the burner makes a complete ring around the base of the horn. Use a short extension cord as voltage drops with a long cord, limiting the amount of heat generated by the dehorner.

Technique

1. Wear gloves to protect your hands.

2. Hold the calf’s ear out of the way to keep it from being burned.

3. Preheat the dehorning iron to a red colour. Both electric and gas irons work best when they are "red" hot.

4. Place the tip of the burner over the horn and apply slight pressure. When the burning hair begins to smoke, slowly rotate the dehorner by twisting your wrist.

5. Continue the application of heat for 10 to 15 seconds. Do not leave the dehorner in place for much longer, especially in young calves. Heat can be transferred through the thin bones of the skull and damage the calf’s brain.

6. Dehorning is complete when there is a copper-coloured ring all the way around the base of the horn.

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Dehorning Spoon or Tube

With this method, a sharpened metal tube cuts through and removes the horn-producing skin at the base of the horn bud. Use the proper size tube to remove the horn plus about 1 /8 inch of skin around the entire horn bud.

Technique

1. Place the cutting edge of the tube over the horn bud. Centre it over the bud.

2. Apply pressure to the tube; push and twist the tube until the skin has been cut through.

3. Cut under the horn bud and remove it, using a scooping motion.

4. Apply an antiseptic to the wound. Clean and disinfect the cutting edge of the tube between calves.

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Gouge or Barnes-Type Dehorner

With this method, the dehorner rapidly removes the horn bud and horn-producing skin. The dehorner is suitable for dehorning calves with horns up to 4 inches long. The blades must be kept sharp for best results.

Technique

1. Close the handles together.

2. Place the jaws of the dehorner over the horn bud. The objective is to completely remove a ring of skin surrounding the horn base.

3. Press the gouger gently against the head. Maintain the pressure and quickly spread the handles apart to remove the horn and skin.

4. Control bleeding by pulling the arteries with forceps or using a hot iron to cauterize the artery.

5. Clean and disinfect the jaws of the gouger between calves.

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Blocking the Nerve to the Horn

One nerve provides the feeling to each horn. The technique makes dehorning easier on the calf and on the person doing the job. You must block one nerve on each side of the head. The lidocaine anaesthetic is a prescription drug and is only available from your veterinarian.

Technique

1. Restrain the calf with a halter tied to a ring, a post, or the head gate of the chute.

2. For calves, use an 18 gauge by 1 inch needle and 5 cc of lidocaine with epinephrine for horn.

3. Locate the injection site by putting your thumb on the skin just beside the outside corner of the eye. You will feel a soft depression at this site. Now, move your thumb backwards toward the horn. You will feel a small groove that runs in the bone of the skull. The nerve runs along and under this groove. The injection site is midway between the corner of the eye and the base of the horn.

4. While holding the head steady and with the needle on the syringe, push the needle through the skin at the injection site. The needle should penetrate perpen-dicular to the skull at the site. Once you are through the skin, inject about 1.5 cc of lidocaine. Push the needle in about 1 /4 inch and inject another 1.5 cc. Push it in about another 1 /4 inch and inject the last 2Ê cc of lidocaine. Then withdraw the needle. If you hit the bone with the tip of the needle, withdraw it slightly and give the last of the lidocaine.

5. Repeat on the other side of the head. The lidocaine is similar to the product used by dentists to freeze your tooth. You may need to wait several minutes for it to take effect. Proceed to block the nerves on other calves and then return to dehorn the first calf.

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