Conditioned place preference reveals ongoing pain in calves 3 weeks after disbudding

Area of Science:

• Veterinary Science
• Animal Welfare
• Pain Research

Background:

• Hot-iron disbudding is a common practice to prevent horn growth in calves.
• While acute pain is recognized, the existence of chronic, non-evoked pain post-disbudding remains uninvestigated.
• Understanding long-term pain is crucial for improving animal welfare.

Purpose of the Study:

• To investigate if calves experience ongoing pain 3 weeks after hot-iron disbudding.
• To assess the willingness of disbudded calves to seek analgesia.
• To evaluate the welfare implications of disbudding procedures.

Main Methods:

• A conditioned place preference test was used with 44 calves.
• Calves were either disbudded or sham-disbudded 6 hours or 20 days before testing.
• Analgesia was induced using a lidocaine cornual nerve block, paired with a visual stimulus.

Main Results:

• Calves disbudded 6 hours prior showed a preference for the analgesia-associated stimulus.
• Calves disbudded 20 days prior did not avoid the aversive stimulus associated with lidocaine, suggesting a trade-off for pain relief.
• Sham-disbudded calves on Day 20 avoided the lidocaine stimulus, indicating it's aversive to uninjured animals.

Conclusions:

• Calves experience persistent pain for at least 3 weeks following hot-iron disbudding.
• The willingness of disbudded calves to seek analgesia highlights significant welfare concerns.
• This study underscores the need for improved pain management strategies in cattle.