When is the right time to disbud? What methods are the least painful? Why bother with painrelief? This short article looks to answer these questions while providing some of the latestinformation on disbudding dairy calves. The main take-home message from this article is thatdisbudding should be performed on calves up to 7 days old with paste, or calves 1 to 6 weeksold with a hot-iron disbudder using short- and long-term pain management protocolsdeveloped with your veterinarian.
Disbudding calves younger than 6 weeks old
Most dairy animals naturally grow horns that must be removed to prevent harm to people andother animals. Horns can be removed from calves while the horn is still in the bud stage(disbudding), or by method of amputation in older animals (dehorning).
The best method of removing horns in cattle is disbudding at the earliest possible age.Disbudding is the removal of the corium while still in the bud phase. The ideal time to disbudis when animals are very young and when the bud is just erupting. This reduces the likelihoodof complications, such as infection or bleeding. However, the age that disbudding occurs isalso dependent upon the removal technique. These include electric hot-iron disbudding andpaste disbudding.
Horns begin to grow at or soon after birth. Horns grow from buds that float freely in tissuewhile the calf is young. However, at about 2 months of age, the horn bud attaches to the skulland grows as an extension of the skull. Once the horn is attached to the skull, part of thetender sinus above the eyes merges with the horn; consequently making hot-iron or pastedisbudding no longer an option. The removal of horns in older animals—referred to asdehorning—is a more painful surgical procedure because of the fusion of the sinus and horn.Dehorning can lead to bleeding and a higher risk of infection. Additionally, if the proceduredoes not completely remove the corium (horn-growing cells), horn tissue will continue togrow.
The best time for paste disbudding is before 2 days of age, which is when the location of thebud can just begin to be felt. Paste disbudding is best performed as early as possible; after 2days the calf is more likely to rub the paste off, and is able to balance on three legs to scratchits head. Paste disbudding should not be implemented on animals older than 7 days of age.When the calf is 1 to 6 weeks of age, the best method for disbudding is electric hot-irondisbudding; so it is completed before the horn attaches to the skull. At this young age it is theleast painful time for this procedure because the horn is still free floating; however, short andlong-term pain management is required.
Providing pain relief: anaesthetics and NSAIDs
There is no doubt that disbudding is a painful procedure. After being subjected to acute pain,calves show increased behavioral responses, such as ear flicking, head shakes, and a changein resting, feeding behavior, and ruminating if older. The 'stress hormone' cortisol alsoincreases during and after a painful procedure. Additionally, recent research suggests thatcalves experience a negative emotional response for up to 22 hours after disbudding.Additional research indicate that many of these behavioral and physiological responses canbe reduced or avoided by providing suitable methods of pain relief.
No matter which method of disbudding is used, local anaesthetic and nonsteroidal antiinflammatorydrugs (NSAIDs) should always be used to alleviate pain during and afterdisbudding. Additionally, sedatives, such as xylazine, can be used before disbudding toensure ease of handling, and to protect the person and animal from harm during theprocedure. Sedatives, however, do not serve as pain relief, only to pacify behavior; therefore,a pain management protocol is still necessary. In the United States, in the absence ofcompounds specifically licensed for pain relief in cattle, extra-label drug use regulationsallow for unapproved analgesic drugs to be administered by or under the supervision of aveterinarian provided such use does not result in a violative tissue residue. Welfare programs,such as the FARM program, require pain management protocols for painful procedures likedisbudding.
Local anaesthesia and post-operative analgesics (such as NSAIDs) mitigate pain anddrastically reduce the pain response in calves. The most common local anaesthetic islidocaine, which is only effective in minimizing pain for a short period after injection (about2 hours). Therefore, a long-acting NSAID such as ketoprofen or meloxicam, should be usedto treat pain after the local anaesthetic wears off.
Some of the least painful methods of disbudding are electric hot-iron disbudding with a localanaesthetic at the cornual nerve and around the base of each horn, and paste disbudding with
a local anaesthetic near the cornual nerve. Both methods should always be accompanied by apost-operative analgesic, such as meloxicam or ketoprofen (NSAIDs), to treat the longer-termpain after the immediate pain of the procedure has been addressed. Research indicates thatcalves receiving all 3 medications (sedative, local anaesthetic, and NSAID) have a reducedpain response to caustic paste or hot-iron disbudding procedures.
In summary, calves being disbudded should always have pain relief. We suggest developing asedation and pain management protocol with your local veterinarian for the extra label use ofdrugs on calves for disbudding on your dairy farm. A veterinarian must prescribe any extralabel use of drugs.
Take home messages:
- Removing horn buds from a calf is much easier and less painful than removing the hornafter it attaches to the skull.
- Aim to disbud calves before 2 days of age with paste, or calves 1 to 6 weeks old with ahot-iron disbudder.
- Always use sedatives, local anaesthetics, and NSAIDs when disbudding to improveanimal welfare level.
- Develop a sedation and a pain management protocol or a calf care SOP with your localveterinarian.
- Consider using polled genetics.
Authors:Lori N. Grinter, Donna M. Amaral-Phillips, and Joao H.C. Costa
