Could Caustic Paste Trigger Bad Memories for Calves?

Do you prefer a certain disbudding method over another? You may not be the only one. A recent study conducted by the University of British Columbia shows that calves might have a certain preference, too.

Published in the October issue of the Journal of Dairy Science, the study compared the emotional experience of disbudding calves via caustic paste versus a hot iron. Fourteen bull calves were disbudded by both methods, using caustic paste on one bud and the hot iron on the other, within a 48-hour period. For all treatments, calves received a sedative, local anesthetic and analgesic. After receiving one treatment, the calf was placed in a distinctly marked pen that indicated the method used, then was left in that area for 6 hours to recover.

Calves were then tested for conditioned place aversion at the 48, 72, and 96-hour mark after their last treatment. During the tests, the calves were placed in a neutral pen connected to both the caustic paste and hot iron treatment pens where each calf had previously been disbudded. The time the calves spent in each treatment pen was recorded until the calves chose to lie down.

During the first test (48-hours after the last disbudding), the calves spent more time in the pen associated with the hot-iron disbudding method compared to the pen that used the caustic paste method. These results suggest that calves initially remember caustic paste disbudding as a more negative experience than hot-iron disbudding, even with the use of sedation, local anesthesia, and analgesia.

There is scientific evidence that both disbudding and dehorning are painful procedures, according to Farmers Assuring Responsible Management (FARM). The term “disbudding” refers to the destruction or excision of horn producing cells before skull attachment, while “dehorning” involves the excision of the horn after skull attachment.

While no method is completely pain free, caustic paste can still be used to effectively disbud calves when used with extreme care. If you plan to disbud calves with caustic paste on your operation, remember these simple pain management tips provided by the FARM Animal Care Reference Manuel:

• The younger, the better. Calves should only be a few days old before the paste can be applied. The horn bud should be able to be felt, but not yet attached to the skull. Caustic paste should not be applied to calves more than one week old as it becomes more difficult to prevent the calf from rubbing the paste off.
• Use pain management drugs. Administration of local anesthesia, non-steroidal anti-inflammatory drugs and sedatives all have been shown to provide benefit to calf welfare.
• Don’t use too much paste. Less than a quarter-sized amount paste is needed to remove buds. Apply a thin, even coating, and consider applying a small ring of Vaseline around the surrounding skin to prevent unnecessary irritation.
• Keep the paste dry. If calves are kept outside, make sure to keep them dry. Rain could cause the paste to run into the calf’s eye, potentially causing blindness.
• Apply only one application. If the bud is not removed the first time the caustic paste is applied, do not try to apply again! It may be necessary to use a hot-iron a few weeks later to fully remove the horn.
• Consult your veterinarian. Your veterinarian should be a valuable member of your team. Work with them to develop disbudding and pain management protocols and reevaluate those protocols each year.