Department of Animal and Food Sciences, Texas Tech University, Lubbock 79409.
J Anim Sci. 2012 Jul;90(7):2211-21. doi: 10.2527/jas.2011-4260. Epub 2012 Jan 20.
Surgical castration is a common management practice performed on male pigs to prevent the occurrence of boar taint. Surgical castration is known to cause physiological and behavioral changes in pigs indicative of pain-induced distress; however, it is commonly performed without pain relief. The objective of this study was to evaluate the effectiveness of carbon dioxide gas (CO(2)) anesthesia and a non-steroidal anti-inflammatory drug (NSAID) to alleviate the pain caused by castration. At 3 d of age, male pigs were either control handled (CON), castrated without pain relief (CAS), given an NSAID and then immediately castrated (CAS+NSAID), anesthetized with CO(2) and then castrated (CAS+CO2), or anesthetized with CO(2) and given an NSAID at the time of castration (CAS+BOTH). Blood samples were collected before castration, and at 30, 60, 120, and 180 min, 24 h, and 3 d after castration or handling for analysis of cortisol, C-Reactive protein (CRP), and substance-P (SP) concentrations. This study was then repeated using the same treatment groups, and the behavioral response to castration and handling were measured using a 1-min scan sampling procedure. The percentage of stress vocalizations was recorded during the administration of all treatments. Anesthesia and analgesia did not effectively reduce (P > 0.05) the cortisol response to surgical castration. Overall, CRP concentrations were greater (P < 0.05) in CAS+CO2 pigs as compared with CON pigs. Sixty minutes after castration or handling, SP concentrations were greater (P < 0.08) in pigs given CO(2) anesthesia (CO2, CAS+CO2, and CAS+BOTH) than CON, CAS, and CAS+NSAID pigs. Pigs castrated without pain relief spent more (P < 0.001) time lying without contact than all other treatments during the first 30 min after castration, but thereafter CAS+CO2 pigs spent more (P < 0.001) time lying without contact than other treatments. During the first 30 min after the treatments were applied, CAS+CO2 pigs spent more (P < 0.01) time displaying pain-like behaviors than CON, CAS, CAS+NSAID, and CAS+BOTH pigs. The percentage of stress vocalizations was greater (P < 0.05) in CAS and CAS+NSAID pigs than all other treatments. Neither CO(2) anesthesia nor a NSAID, given separately or combined, markedly reduced the pain-induced distress caused by castration in pigs. More research is needed to evaluate practical methods of on-farm pain relief for pigs.
去势是一种常见的公猪管理实践，用于防止公猪产生异味。众所周知，去势会导致猪出现疼痛引起的不适的生理和行为变化；然而，通常在没有缓解疼痛的情况下进行去势。本研究的目的是评估二氧化碳（CO 2 ）麻醉和非甾体抗炎药（NSAID）缓解去势引起的疼痛的效果。在 3 日龄时，雄性仔猪要么进行对照处理（CON），要么不进行疼痛缓解的去势（CAS），要么在去势前给予 NSAID 后立即去势（CAS+NSAID），要么用 CO 2 麻醉后去势（CAS+CO 2 ），要么在去势时用 CO 2 和 NSAID 麻醉（CAS+BOTH）。在去势或处理前、去势后 30、60、120 和 180 分钟、24 小时和 3 天采集血液样本，分析皮质醇、C 反应蛋白（CRP）和 P 物质（SP）浓度。然后，使用相同的处理组重复进行该研究，并使用 1 分钟扫描采样程序测量对去势和处理的行为反应。在所有治疗过程中记录应激发声的百分比。麻醉和镇痛并不能有效降低（P > 0.05）手术去势引起的皮质醇反应。总体而言，与 CON 仔猪相比，给予 CO 2 麻醉的仔猪（CAS+CO 2 ）的 CRP 浓度更高（P < 0.05）。去势或处理后 60 分钟，接受 CO 2 麻醉的仔猪（CO 2 、CAS+CO 2 和 CAS+BOTH）的 SP 浓度高于 CON、CAS 和 CAS+NSAID 仔猪（P < 0.08）。未进行疼痛缓解的去势仔猪在去势后 30 分钟内比其他所有处理方式都花更多（P < 0.001）的时间躺着不动，没有任何接触，但此后，与其他处理方式相比，CAS+CO 2 仔猪花更多（P < 0.001）的时间躺着不动，没有任何接触。在应用治疗后的头 30 分钟内，与 CON、CAS、CAS+NSAID 和 CAS+BOTH 仔猪相比，CAS+CO 2 仔猪表现出更多（P < 0.01）的类似疼痛行为。与所有其他治疗方式相比，接受 CAS+CO 2 治疗的仔猪的应激发声百分比更高（P < 0.05）。CO 2 麻醉或 NSAID 单独或联合使用均未显著减轻去势引起的疼痛引起的仔猪不适。需要进一步研究以评估猪在农场缓解疼痛的实用方法。
