Di Giminiani Pierpaolo, Stausholm Julie S, Viitasaari Eliina, Petersen Lars J, Herskin Mette S
Department of Animal Science, AU-FOULUM, Aarhus University, Tjele, Denmark.
Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
Vet Anaesth Analg. 2015 Nov;42(6):648-56. doi: 10.1111/vaa.12254. Epub 2015 Mar 8.
To investigate the effects of habituation and isolation on mechanical nociceptive thresholds in pigs at the pelvic limbs and at the tail.
Prospective randomized multifactorial study.
Thirty-two healthy castrated male (experiment 1), and 12 castrated male and 12 female (experiment 2) Danish Landrace×Yorkshire pigs, weighing 63.5±0.8 kg and 55.4±0.6 kg (the mean±SD, experiment 1 and 2, respectively).
Mechanical nociceptive thresholds were quantified with a von Frey anesthesiometer applied to two distinct anatomical regions (tail and pelvic limbs). Pigs receiving the mechanical challenge in the pelvic limbs were tested inside a cage, whereas pigs exposed to stimuli at the tail region were tested in an open arena. For both experiments, the effect of familiarity to the procedure was evaluated by comparing thresholds of nociception in habituated versus naïve pigs. The presence of a companion animal was also evaluated in pigs receiving stimuli at the pelvic limbs.
Pigs tested inside the cage were affected by the habituation to the procedure as indicated by the increase in willingness and time spent by the animals in the test cage. This effect was reflected in the lower mechanical nociceptive thresholds (medians with 25-75 percentiles) recorded for familiar pigs compared with naïve animals [495 g (302-675) versus 745 g (479-1000), respectively; p=0.026]. Mechanical nociceptive thresholds measured at the tail of the pigs in the open arena were not affected by the familiarity of the animals with the experimental procedure.
The current results reiterate the value of habituation in research involving animal behaviour. Further characterization of the methodology is needed to allow its application in the evaluation of clinical conditions in pigs.
研究适应和隔离对猪后肢及尾部机械性伤害感受阈值的影响。
前瞻性随机多因素研究。
32头健康去势雄性猪（实验1），以及12头去势雄性猪和12头雌性猪（实验2），丹麦长白猪×约克夏猪，体重分别为63.5±0.8千克和55.4±0.6千克（均值±标准差，分别为实验1和实验2）。
使用von Frey麻醉计对两个不同解剖区域（尾部和后肢）进行机械性伤害感受阈值的量化。在后肢接受机械刺激的猪在笼内进行测试，而在尾部区域接受刺激的猪在开放场地进行测试。对于两个实验，通过比较适应组和未适应组猪的伤害感受阈值来评估对实验过程的熟悉程度的影响。在接受后肢刺激的猪中也评估了同伴动物的存在情况。
如动物在测试笼中的意愿和停留时间增加所示，在笼内测试的猪受到对实验过程适应的影响。这种影响反映在与未适应动物相比，适应组猪记录的机械性伤害感受阈值较低（中位数及25%-75%百分位数）[分别为495克（302-675）和745克（479-1000）；p=0.026]。在开放场地中猪尾部测量的机械性伤害感受阈值不受动物对实验过程熟悉程度的影响。
当前结果重申了适应在涉及动物行为研究中的价值。需要对该方法进行进一步表征，以便其应用于猪临床状况的评估。
