Disbudding and dehorning are used to remove the horns of cattle which are of horned breeds.
It is generally acknowledged that dehorning and disbudding of cattle, by whatever means, causes pain.
Dehorning, by whatever method, involves destruction of tissue and "it is apparent that calves experience stress and pain."
The integrated cortisol response in the first two hours was significantly greater for calves subject to scoop dehorning than for those dehorned by cautery with or without local anaesthesia and those dehorned by scoop following local anaesthesia. The integrated cortisol response after two hours was significantly higher for scoop dehorned calves given local anaesthesia than for those dehorned by cautery with or without local anaesthetic, control handled calves and those given local anaesthetic without dehorning. For the entire 9.5 hours after dehorning there was no significant difference between calves disbudded by scoop or cautery. (J10.44.w2).
May potentially cause additional harm to the animal.
Disbudding by cautery is probably less painful than disbudding by other methods such as scoop disbudding. There is no evidence that any one method of dehorning (of older animals) is more or less painful than other methods.
Use of local anaesthetics prior to disbudding or dehorning prevents pain sensation at the time of the disbudding or dehorning. However, behavioural evidence as well as plasma cortisol measurements indicate that pain is felt once the local anaesthetic wears off. Even if an additional dose of long-acting local anaesthetic is given while the first dose is still in effect, pain appears to develop after the period of action of the second local anaesthetic.
Calves of four to six weeks old provided with local anaesthesia (cornual block with lidocaine plus local deposition of lidocaine caudal and medial to the horn bud) before hot dehorning showed marked and generally significant behavioural signs of pain both during and in an observation period of four hours after dehorning compared to calves not given analgesia. subjected to hot iron dehorning without analgesia, and also showed significant differences in ACTH and cortisol responses. (J288.62.w1).
Administration of the sedative xylazine has some pain relieving effect on calves subjected to dehorning.
Administration of xylazine (0.2 mg/kg intravenously) to calves of four to eight weeks old eliminated responses to injection of local anaesthetic agent into the cornual nerve area and as a ring block around the horn base.
Specific published reasons for failure to provide pain relief for disbudding and dehorning of cattle are indicated below.