Effects of administration of a local anaesthetic and/or an NSAID and of docking length on the behaviour of piglets during 5h after tail docking

Abstract

In many countries, piglets are tail docked to prevent tail biting. The aim of this study was 1) to evaluate the efficacy of a local anaesthetic and/or NSAID to reduce pain caused by tail docking; and 2) to examine interactions with docking length. This was examined in 295 piglets docked by hot iron cautery 2-4days after birth and based on behaviour during docking as well as the following 5h. The study involved three main factors: local anaesthetic (Lidocain), NSAID (Meloxicam) and docking length. Either 100%, 75%, 50% or 25% of the tails were left on the body of the piglets. Irrespective of the tail length, tail docking led to signs of procedural pain, which could be reduced by administration of Lidocain. Preemptive use of Meloxicam did not affect the signs of procedural pain. The results show that tail docking led to behavioural changes throughout the 5h observation period indicating that effects of this management routine are more persistent than earlier suggested, and suggesting that docking length may influence the post-surgical behaviour of piglets. By use of the present sites of injection and dosages, neither local anaesthetic nor NSAID had marked effects on post-surgical behavioural changes induced by tail docking. Hence, if tail docking is to be performed, more research is needed in order to develop practical methods for on-farm piglet pain relief.

Keywords: Amputation; Behaviour; Pain; Pig; Tail docking.