REDUCTION IN PAIN SUFFERED BY LAMBS AT CASTRATION

The acute pain produced by bloodless castrators was studied by compari ng the behavioural and plasma cortisol changes in groups (n=8) of 3-we ek-old Dorset cross lambs after castration with a 22 cm (9 '') Burdizz o, a new power assisted castrator and by a combined method using a Bur dizzo and elastrator ring. The time spent in abnormal postures (52-58 min) and the peak cortisol response (110-120 mmol l(-1)) were similar for the three methods, although the powered castrator produced a more sustained response. The Burdizzo method halved the incidence of active behaviours compared with the powered castrator and combined methods ( 16 versus 30, 32 counts). Intratesticular local anaesthetic administer ed 2 min before the Burdizzo castrator and combined method, or intramu scular injection of the non-steroidal anti-inflammatory drug diclofena c, 20 min before the application of a Burdizzo, significantly reduced the peak plasma cortisol response to 80 nmol l(-1). Diclofenac also si gnificantly reduced the time spent trembling or in abnormal postures.