Kent J E, Molony V, Graham M J
Department of Preclinical Veterinary Sciences, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Scotland.
Vet J. 1998 Jan;155(1):39-51. doi: 10.1016/s1090-0233(98)80033-6.
Behavioural and plasma cortisol changes were recorded for groups of eight Suffolk x Greyface lambs subjected to castration or tail docking using rubber rings with and without local anaesthetic treatment. Immediately after application of the rubber ring, local anaesthetic (2 x 0.2 ml 2% lignocaine) was administered either by needle and syringe or by high-pressure needleless injection into each side of the neck of the scrotum or tail at the site of the ring, or by high pressure needleless injection into the testes before ring application. In other groups, the innervation to the scrotum or tail was disabled by crushing with a powered bloodless castrator just proximal to the ring. Measurements were recorded in groups of control (handled) lambs, with and without local anaesthetic treatment. Application of local anaesthetic by high pressure needleless injection had little effect on either plasma cortisol values or behaviour of control lambs. For castration, application of the bloodless castrator and/or local anaesthetic at the ring site reduced the peak plasma cortisol concentration by 50% (P < or = 0.01), the incidence of active behavioural responses by 80 and 64% (P < or = 0.01) respectively, and the time spent in abnormal postures by 68 and 59% (P < or = 0.01) respectively. Both methods were effective in reducing pain for tail docking [active behavioural responses reduced by more than 80% (P < or = 0.01) and abnormal postures by 56% (P < or = 0.01)], although local anaesthetic was more effective, reducing the peak cortisol by 60% (P < or = 0.01) [crushing by 44% (P > 0.05)]. Injection of local anaesthetic into the testes was less effective than injection into the neck of the scrotum at the site of the ring [reduction in abnormal lying postures (P < or = 0.05), 45 vs 71%, respectively]. The rapid action, effectiveness, and ease of application of these experimental methods may provide the basis for commercially viable methods for reducing the acute pain produced by rubber ring castration and tail docking of lambs.
对八组萨福克×灰脸杂交羔羊进行了行为和血浆皮质醇变化记录，这些羔羊分别接受了使用橡胶环进行阉割或断尾处理，处理过程中有的使用了局部麻醉，有的未使用。在套上橡胶环后，立即通过针头和注射器，或者通过高压无针注射，在阴囊或尾巴套环部位的颈部两侧注射局部麻醉剂（2×0.2毫升2%利多卡因），或者在套环前通过高压无针注射到睾丸中。在其他组中，在套环近端使用电动无血去势器挤压，使阴囊或尾巴的神经支配失效。在有或没有局部麻醉处理的对照组（经处理）羔羊组中进行测量记录。通过高压无针注射局部麻醉剂对对照组羔羊的血浆皮质醇值或行为影响很小。对于阉割，在套环部位使用无血去势器和/或局部麻醉剂可使血浆皮质醇峰值浓度降低50%（P≤0.01），主动行为反应发生率分别降低80%和64%（P≤0.01），异常姿势持续时间分别降低68%和59%（P≤0.01）。两种方法在减轻断尾疼痛方面均有效[主动行为反应降低超过80%（P≤0.01），异常姿势降低56%（P≤0.01）]，尽管局部麻醉更有效，可使皮质醇峰值降低60%（P≤0.01）[挤压法降低44%（P>0.05）]。在睾丸中注射局部麻醉剂不如在阴囊套环部位的颈部注射有效[异常躺卧姿势减少（P≤0.05），分别为45%和71%]。这些实验方法的快速起效、有效性和易于应用，可能为减少羔羊橡胶环阉割和断尾产生的急性疼痛的商业可行方法提供基础。
