Disbudding

When to disbud a calf

Early disbudding is better for both the calf and the operator. It is best to remove horn buds before six weeks of age. At this age, the horns are still small and have not yet attached to the skull.

It is recommended that calves are at least a week old before disbudding. Calves at this age are usually robust, have passed the greatest risk period for scours, and the horn bud is easily felt.

Horn development

Horn bud before 8 weeks old (left) and around 6 months old (right)

The horn bud is free-floating in the skin over the skull in calves less than about eight weeks old, although this timeframe can vary.

As the calf grows, the horn bud attaches to the skull bone, a small horn forms and the sinus grows into the horn. Dehorning after the horn attaches increases the risk of burning the skull, exposing the sinus or leaving a larger wound.

Restraining a calf to be disbudded

To administer local anaesthetic and apply the hot iron, calves will need to be restrained to disbud safely and accurately. This may be in a purpose designed disbudding crate or in a head bail.

Another option for restraint is sedation, which can only be done by a vet. Sedation results in low stress disbudding for calves and handlers, and is ideal when other options for restraint are inadequate.

Pain relief when disbudding

There are many benefits of using pain relief, including:

• less pain for the calf
• less stress for the calf
• reduced growth check
• reach weaning weight sooner
• faster recovery
• the calf is easier to handle during disbudding.

Options for pain relief

Local anaesthetic must be used when disbudding or dehorning an animal at any age and by any method. Local anaesthetic numbs the horn bud for about two hours. Using an anti-inflammatory or a topical anaesthetic as well will provide longer term pain relief for the calf. The graph below shows the effect of pain relief options.

Cortisol is measured in the blood and indicates pain or stress.

If you would like to administer local anaesthetic yourself, you will need to discuss with your vet whether it is a possibility for your farm.

Methods of horn bud removal

All methods of disbudding require local anaesthetic.

Hot iron cautery is the most effective method used to disbud calves, and is used by 97% of farmers. Calves should be disbudded by hot iron between one and six weeks old.

Caustic paste should not be used as it can spread into the eyes or onto other calves, causing painful burns. There is also not currently a local anaesthetic that lasts long enough for use with caustic paste.

Scoop/amputation should not be used as it leaves a large open wound with risk of bleeding, infection and disease.

Managing groups for disbudding

Providing pain relief should only add a few minutes to the disbudding process. Local anaesthetic takes three minutes to numb the horn bud. Administer the local to the group of calves one by one, and by the time the last calf is injected, the first calf’s horn buds will be numb and ready to be disbudded. If two people are doing the disbudding, one person can administer the local, while the other starts disbudding.

Using a vet or husbandry service provider

There are many benefits to using a contractor:

• you can get on with other work while the disbudding takes place
• they can be scheduled to ensure all calves are done in the optimum window
• they have good, well-maintained equipment and are efficient
• they can usually do other tasks at the same time, such as DNA sampling or removing extra teats.

If you would like to administer local anaesthetic yourself, you will need to discuss with your vet whether it is a possibility for your farm.

Assess your options for pain relief

*The clocks represent farmer time – sedation requires some changes to feeding schedule on the day and monitoring during recovery.

Post-operative care

After disbudding, the wound must be kept dry for 24 hours and calves will need to be housed if rain is expected. Check the calves regularly, and at least daily, for signs of infection or bleeding.

If calves were sedated for disbudding, they should be left sitting upright after the procedure so that they can burp, and to allow the saliva to run out of the mouth until normal swallowing returns. Wait until the calves are up and alert before feeding, this can take around three hours. If any calves are slow to recover to full consciousness, contact your vet.

Polled bulls

Using polled bulls, where available, will reduce the number of animals that need to be disbudded. Polled beef bulls are readily available.

It is difficult to achieve widespread polling in a dairy herd, without compromising breeding for other production or health traits, however polled genetics are becoming more available. Talk to your genetics supplier about using polled genetics across some of your herd.

Dehorning older animals

Dehorning of older animals should be avoided by disbudding them as young calves. However, if animals are purchased with horns or if a horn re-grows and dehorning is required, local anaesthetic must be used, and additional pain relief is recommended.

Tipping (removal of the insensitive sharp end of the horn) is not dehorning. However, the length of the insensitive tip is variable and it isn’t obvious. There is risk of accidentally cutting through and exposing the living tissue. If this happens you have dehorned the animal, and if you haven’t used pain relief then you will be breaching welfare minimum standards. Animals can only be tipped once, as after the first tipping the sensitive tissue of the horn is usually very close to the end of the horn. Tipping also does little to reduce the disadvantages of having horned cattle and these animals can still be a danger to other cattle and handlers.