Early Disbudding of Calves by Cautery Recommended

9 August 1996

Calves should be disbudded before six weeks of age using the cautery, rather than the scoop method. The use of anaesthetic with the cautery method is optional.

This is the finding of Massey University Professor David Mellor’s study into pain-free methods of dehorning or disbudding calves, which until Professor Mellor’s research, had been given relatively little attention.

The purpose of dehorning and disbudding is to minimise injury to both stock and stockhandlers and reduce carcass and hide damage. Dehorning of cattle is a routine procedure which in New Zealand is performed on calves from within a few days of birth to 20 months of age, without the use of local anaesthetic. Dehorning young calves with minimal horn development is called disbudding. Both procedures raise some concerns, because it’s not known how much distress the animal is put through during the procedure and from delayed reactions. All methods of disbudding involve tissue damage and stimulate nerves which carry pain sensations to the brain, which is assumed to cause distress.

In one part of the study, six-week-old calves were disbudded by a variety of methods. This was done to determine whether the response to scoop dehorning was similar to that of cautery disbudding, and how effective the use of local anaesthetic was in reducing the pain when using either of the two methods.

It was found that to virtually abolish the pain of scoop disbudding, the animal needed to be given a combination of local anaesthetic (nerve block) and analgesic (a longer lasting pain killer). Analgesics alleviated the distress to the animal after the local anaesthetic had worn off. However, the cost of injecting both, per head of cattle, would be a deterrent to farmers and Professor Mellor’s preference is to disbud calves by cautery.

“The cautery disbudding of young calves should be preferred to amputation dehorning at any age if no additional pain control is used with either approach,” said Professor Mellor, “and the prior injection of local anaesthetic in young calves disbudded by cautery should be optional at this stage.”

The local anaesthetic used in the study was the same as dentists used, which stops sensations for two-and-a-half-hours. “I can’t say the calves don’t feel anything, but it is likely to be discomfort, rather than outright pain,” said Professor Mellor.

Professor Mellor and his team tested a range of variables, such as differing the time intervals between giving the anaesthetics and analgesics, using the scoop rather than the cautery method and varying the scoop’s depth.

Professor Mellor found cautery disbudding using a cauterising iron, rather than a scoop, would damage the tissue surrounding the horn bud, resulting in third degree burns. Third degree burns
also destroy pain nerve receptors, which is why third degree burns do not cause as much pain as first and second degree burns.

Conclusions drawn from the study were:

  1. Cautery disbudding causes less distress than scoop dehorning.
  2. Prior administration of a local anaesthetic is of little benefit in reducing the overall distress caused by scoop disbudding. However, it does reduce the distress experienced during the first two hours after disbudding, as indicated by fewer attempts by the animal to escape during the horn amputation and afterwards.
  3. There are marginal benefits in the prior administration of local anaesthetic to calves disbudded by cautery. Such calves also showed less tendency to attempt escape in response to the cautery itself.
  4. Although cautery does cause some moderate distress for a short period, it should be used in preference to scoop disbudding in six-week-old calves.

Professor Mellor said that for many years farmers had willingly adopted practices which improved the welfare of their livestock in the areas of good nutrition and the prevention and control of disease.
“Farmers will be just as willing to adopt measures that reduce or eliminate the pain and distress caused by animal husbandry practices, like dehorning, once practical measures become available, and I hope this work will contribute to that development.” He said the study’s findings could also contribute to the control of pain in humans.

Alistair Polson, Federated Farmers vice-president, has come out in support of the research. He said while there was a tendency for the animal welfare debate to be driven by emotion, it was good to see thoroughly researched, scientifically based recommendations that farmers could trust and implement.

“In the light of Professor Mellor’s work, farmers would be well advised to pursue the cautery option in young cattle as opposed to the continued use of the scoop method. The least pain is not only important for the animal, but also ensures the good will of an increasingly aware consumer and general public lobby. The adoption of the cautery technique will demonstrate that farmers do care.”

For further information:

Professor David Mellor
Massey University
ph: 06 3505066

  

 

Last Updated: 07 September 2010

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