Department of Animal and Food Sciences, Pork Industry Institute, Texas Tech University, Lubbock, TX 79409, USA.
Animal. 2011 Jun;5(8):1237-46. doi: 10.1017/S175173111100019X.
Tail docking of pigs is a routine procedure on farms to help control tail-biting behavior; however, docking can cause pain. The objective of this research was to evaluate the effect of local or general anesthesia on the physiology (experiment 1) and behavior (experiment 2) of tail docked pigs. Pigs were allocated to one of six treatment groups: (i) sham docking (CON); (ii) docking using conventional cutting (CUT) with side-cutting pliers; (iii) CUT docking plus local anesthesia injected immediately before docking (LA); (iv) CUT docking plus short-acting local anesthesia applied topically to the tail wound (SHORT); (v) CUT docking plus long-acting anesthesia applied topically to the tail wound (LONG) and (vi) CUT docking while the pig was anesthetized with carbon dioxide gas (CO(2)). In experiment 1, blood samples were collected from pigs (10 pigs per treatment) before and 30, 60 and 120 min after docking to measure leukocyte counts and percentages and cortisol concentrations. In experiment 2, the above treatments were repeated (10 pigs per treatment); the percentage of stress vocalizations were recorded during the administration of the treatments and behavior was recorded for up to 120 min after docking or handling. All pigs were weighed before and 24 h after docking and wound healing was recorded until weaning. The neutrophil/lymphocyte ratio was greater (P < 0.05) in CUT, LA, SHORT and LONG compared with CON pigs. At 30 min, cortisol concentrations were greater (P < 0.05) in CUT, LA, LONG and CO(2) compared with CON pigs. Cortisol concentrations did not differ (P > 0.05) between SHORT and CON pigs 30 min after docking. Cortisol concentrations did not differ (P > 0.05) among pigs given pain relief at the time of docking compared with pigs' docked without pain relief. Body weight change and wound scores did not differ (P > 0.05) among treatments. The percentage of stress vocalizations increased (P < 0.05) in CUT, SHORT and LONG, but not in CON, LA and CO(2) pigs in response to docking or handling. The percentage of time pigs spent lying without contact after docking tended to be greater (P = 0.06) in CUT pigs compared with all other docking treatments and CON pigs. In this study, none of the anesthesia treatments tested were effective at significantly changing the physiological or behavioral response to tail docking in pigs.
给猪断尾是农场控制咬尾行为的常规程序，但断尾会引起疼痛。本研究的目的是评估局部或全身麻醉对断尾猪的生理（试验 1）和行为（试验 2）的影响。猪被分配到以下六组之一：（i）假手术（CON）；（ii）用侧切钳进行常规切割（CUT）；（iii）在断尾前立即注射局部麻醉（LA）；（iv）局部麻醉剂短时间涂抹于断尾伤口（SHORT）；（v）长效麻醉剂长时间涂抹于断尾伤口（LONG）；（vi）用二氧化碳气体（CO(2)）麻醉猪时进行 CUT 断尾。在试验 1 中，在断尾前（10 头猪/处理）和断尾后 30、60 和 120 分钟采集猪的血液样本，以测量白细胞计数和百分比以及皮质醇浓度。在试验 2 中，重复上述处理（10 头猪/处理）；在处理过程中记录应激发声的百分比，并在断尾或处理后长达 120 分钟记录行为。所有猪在断尾前和断尾后 24 小时称重，并记录伤口愈合情况，直到断奶。与 CON 猪相比，CUT、LA、SHORT 和 LONG 猪的中性粒细胞/淋巴细胞比值更高（P<0.05）。在 30 分钟时，与 CON 猪相比，CUT、LA、LONG 和 CO(2)猪的皮质醇浓度更高（P<0.05）。在断尾后 30 分钟，SHORT 组和 CON 组的皮质醇浓度没有差异（P>0.05）。与未接受疼痛缓解的猪相比，在断尾时接受疼痛缓解的猪的皮质醇浓度没有差异（P>0.05）。体重变化和伤口评分在处理之间没有差异（P>0.05）。与 CON、LA 和 CO(2)猪相比，在断尾或处理过程中，CUT、SHORT 和 LONG 猪的应激发声百分比增加（P<0.05）。断尾后，猪无接触躺着的时间百分比（P=0.06）趋于在 CUT 猪中大于所有其他断尾处理和 CON 猪。在这项研究中，没有一种测试的麻醉处理在显著改变猪对断尾的生理或行为反应方面是有效的。
