New Research on Methods for Alleviating Pain in Farm Animals

Welfare attention on surgical husbandry practices for farm animals focuses on the fact that many of the procedures involve innervated tissues and are traditionally performed without anaesthesia or analgesia. There are several approaches available for addressing welfare concerns surrounding these procedures. These options include 1) cessation of the procedure in combination with altered management strategies; 2) breeding animals that do not require the procedure; 3) replacing the current procedure with a non-surgical alternative that has been shown to optimise welfare; or 4) performing the procedure without pain. This paper examines the fourth approach. Previous published research has examined analgesic strategies for the castration and dehorning of cattle and the castration of lambs. Recent published research by the CSIRO has examined the effectiveness of analgesic approaches for mulesing of sheep. The options included topical local anaesthesia and the administration of carprofen and flunixinboth non-steroidal anti-inflammatory drugs (NSAIDs). Currently, NSAIDs are not registered for use in sheep in Australia and the topical anaesthetic is available for sheep only under a minor use permit. The administration of NSAIDs alone provided some behavioural benefits but did little to reduce plasma cortisol. The administration of the topical anaesthetic alone had benefits in terms of reduced cortisol immediately after mulesing and less hunched standing compared with no treatment. Greatest pain relief, as indicated by the behavioural and cortisol responses to mulesing, was provided by the combined administration of the commercially-available topical local anaesthetic formulation and the long acting NSAID carprofen. In effect, this treatment showed that it is scientifically possible to abolish the pain responses occurring in the hours after mulesing.