The disbudding of replacement heifer calves is a job that is looming on many dairy farms, and should be completed before calves get too big.
The disbudding of calves is carried out to comply with regulations under the Diseases of Animals Act (1966) which prohibits the sale or export of horned animals.
Disbudding procedures must be carried out in compliance with the Protection of Animals (Amendment) Act (1965).
It is illegal to disbud a calf over two-weeks-old without using a local anaesthetic. The veterinary advice is that all calves should be treated with a local anaesthetic when disbudding.
Local anaesthetic may be obtained by prescription from veterinary surgeons.
Disbudding
The main method of disbudding calves is cauterisation.
Cauterisation is the method preferred by most farmers and the use of caustic paste for disbudding calves is illegal, irrespective of age.
Farmers should be well aware of how to remove the bud when using the cauterisation method:
- Restrain the calf, preferably using a custom-built calf-dehorning crate;
- Identify the location of the buds and administer anesthetic of 2-3ml on both sides. Consult your vet regarding their procurement and application/administration;
- Prior to disbudding it may be useful to clip the hair around the horn bud so that it can be seen easily and a clean burn can be achieved;
- Place the hot iron on the bud and rotate it in a half circle 10-12 times while applying pressure. Angle the instrument so that the edge burns the skin around the rim of the bud;
- Dig out the horn by pressing and moving the head of the iron laterally, leaving a crater in the skin. There may be a small protrusion in the centre of the hollow but this may be left as it is not horn-forming tissue;
- Remove the other horn bud in the same manner.
Vets
A method that has been common place in many other countries, has been putting calves under aesthetic to disbud them.
This involves putting all the calves that are being disbudded to sleep and removing the buds then.
For this method, a vet is needed and there will also be an increased cost associated with it. All of the calves will be disbudded in a short space of time and in one group, rather than doing a few at a time.
Consider the weather
Changes in the weather can increase the level of stress calves are under, so calves should be disbudded when the weather is mild.
Completing a job when calves are already under stress can prolong the recovery time of the calves.
Ideally, you want the calves to return to normal behaviour as soon as possible after the disbudding has taken place.
If calves are under increased stress when the job is completed, the likelihood is that they will not return to normal behaviour and this could delay their growth and or development.
Monitoring
You should avoid the use of antibiotics during the removal of horns from calves. Instead, you should give them anti-inflammatories to help with pain management.
This should reduce the amount of time the calf spends not drinking or eating.
Calves need to be monitored for around 10 days after disbudding for monitoring of infections or fly strike.
Common symptoms to look out for are constant tossing of the head and/or a discharge from the wound.
If signs of infections are seen in the calves, you should consult with your vet to see what treatment is required.