Stock M L, Barth L A, Van Engen N K, Millman S T, Gehring R, Wang C, Voris E A, Wulf L W, Labeur Léa, Hsu W H, Coetzee J F
J Anim Sci. 2016 Feb;94(2):542-55. doi: 10.2527/jas.2015-9510.
The objective of this study was to investigate the effects of carprofen administered immediately before cautery dehorning on nociception and stress. Forty Holstein calves aged approximately 6 to 8 wk old were either placebo treated and sham dehorned ( = 10) or cautery dehorned following administration of carprofen (1.4 mg/kg) subcutaneously ( = 10) or orally ( = 10) or a subcutaneous and oral placebo ( = 10) in a randomized, controlled trial. All animals were given a cornual nerve block using lidocaine before dehorning. Response variables including mechanical nociception threshold, ocular temperature, heart rate, and respiratory rate were measured before and following cautery dehorning for 96 h. Blood samples were also collected over 96 h following dehorning and analyzed for plasma cortisol and substance P concentrations by RIA. Plasma carprofen concentration and ex vivo PGE concentrations were also determined for this time period. Average daily gain was calculated for 7 d after dehorning. Data were analyzed using a linear mixed effects model with repeated measures, controlling for baseline values by their inclusion as a covariate in addition to planned contrasts. Dehorning was associated with decreased nociception thresholds throughout the study and a stress response immediately after dehorning, following the loss of local anesthesia, and 48 h after dehorning compared with sham-dehorned calves. Carprofen was well absorbed after administration and reached concentrations that inhibited ex vivo PGE concentrations for 72 h (subcutaneous) and 96 h (oral) compared with placebo-treated calves ( < 0.05). Carprofen-treated calves tended to be less sensitive ( = 0.097) to nociceptive threshold tests. Overall, at the dosing regimen studied, the effect of carprofen on sensitivity and stress following cautery dehorning was minimal. Consideration of route of administration and dose determination studies may be warranted.
本研究的目的是调查在烧灼去角术之前立即给予卡洛芬对伤害感受和应激的影响。在一项随机对照试验中，40头约6至8周龄的荷斯坦犊牛被分为四组：接受安慰剂处理并假去角（n = 10）；皮下注射（n = 10）或口服（n = 10）卡洛芬（1.4 mg/kg）后进行烧灼去角；或皮下和口服安慰剂（n = 10）。所有动物在去角前均使用利多卡因进行角神经阻滞。在烧灼去角前后96小时测量反应变量，包括机械伤害感受阈值、眼温度、心率和呼吸频率。去角后96小时内还采集血样，通过放射免疫分析法分析血浆皮质醇和P物质浓度。在此期间还测定血浆卡洛芬浓度和体外前列腺素E（PGE）浓度。计算去角后7天的平均日增重。使用线性混合效应模型和重复测量进行数据分析，除了计划的对比外，将基线值作为协变量纳入以控制基线值。与假去角的犊牛相比，在整个研究过程中，去角与伤害感受阈值降低以及去角后立即、局部麻醉消失后和去角后48小时的应激反应有关。与接受安慰剂处理的犊牛相比，卡洛芬给药后吸收良好，其浓度在72小时（皮下）和96小时（口服）内抑制体外PGE浓度（P < 0.05）。接受卡洛芬治疗的犊牛对伤害感受阈值测试的敏感性往往较低（P = 0.097）。总体而言，在所研究的给药方案下，卡洛芬对烧灼去角后的敏感性和应激的影响很小。可能有必要考虑给药途径和剂量确定研究。
