The effect of meloxicam on pain sensitivity, rumination time, and clinical signs in dairy cows with endotoxin-induced clinical mastitis
The effect of meloxicam on pain sensitivity, rumination time, and clinical signs in dairy cows with endotoxin-induced clinical mastitis
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DOI：
10.3168/jds.2012-5855
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发表时间：
2013-05-01
影响因子：
3.5
通讯作者：
Leslie, K. E.
中科院分区：
文献类型：
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作者：
Fitzpatrick, C. E.;Chapinal, N.;Leslie, K. E.
本研究的目的是：(1)评估使用压力测量仪和自动反刍监测系统来评估内毒素诱发的临床乳腺炎对疼痛敏感性和反刍时间的影响；(2)评估非甾体抗炎药美洛昔康对内毒素诱发的临床乳腺炎奶牛疼痛敏感性和反刍时间以及其他临床体征的影响。将25 μ g的大肠杆菌脂多糖（LPS）注入1个未感染的四分之一乳内，诱导12头初产奶牛和12头多产泌乳奶牛的临床乳腺炎。随后，一半奶牛皮下注射美洛昔康（治疗组），另一半奶牛皮下注射相同体积的安慰剂溶液（对照组）。在LPS输注美洛昔康或安慰剂后3天、立即、3小时、6小时、12小时和24小时，通过测量引起对照组和挑战组反应所需的压力差来评估疼痛敏感性。用反刍记录仪从LPS输注前2 d至输注后3 d连续监测反刍情况。同时监测乳腺水肿、体温、细胞评分、干物质摄取量，评价LPS灌注后炎症的发生及持续时间。在对照动物中，与基线相比，LPS输注6小时后，施加在对照组和挑战区（对照组挑战区）的压力差增加了1.1 +/- 0.4 kg的力，表明挑战区疼痛敏感性增加。LPS输注和美洛昔康治疗均未对每日反刍时间产生影响。然而，LPS输注当天的反刍日模式总体上偏离基线模式。注射LPS后，奶牛反刍时间减少，晚些时候反刍时间增加。美洛昔康没有改变体细胞评分或干物质摄入量。然而，与对照组动物相比，美洛昔康治疗的动物在LPS输注后的几小时内乳房水肿较少，体温较低。总之，压力测量仪和反刍记录仪有望成为检测乳腺炎和监测农场恢复的工具。此外，美洛昔康在lps诱导的临床乳腺炎中具有缓解疼痛、降低乳房水肿和体温的有益作用。
The objectives of this study were to (1) evaluate the use of a pressure algometer and an automated rumination monitoring system to assess changes in pain sensitivity and rumination time in response to endotoxin-induced clinical mastitis and (2) evaluate the effect of the nonsteroidal antiinflammatory drug meloxicam on pain sensitivity and rumination time, as well as other clinical signs, in dairy cattle with endotoxin-induced clinical mastitis. Clinical mastitis was induced in 12 primiparous and 12 multiparous lactating dairy cows by intramammary infusion of 25 mu g of Escherichia coli lipopolysaccharide (LPS) into 1 uninfected quarter. Immediately after, half the cows were injected subcutaneously with meloxicam (treated group) and half with the same volume of a placebo solution (control group). Pain sensitivity was assessed by measuring the difference in pressure required to elicit a response on the control and challenged quarter using an algometer 3 d before, immediately before, and at 3, 6, 12, and 24 h after LPS infusion and either meloxicam or placebo injection. Rumination was continuously monitored from 2 d before to 3 d after LPS infusion using rumination loggers. Udder edema, body temperature, somatic cell score, and dry matter intake were also monitored to evaluate the occurrence and the duration of the inflammation after LPS infusion. In control animals, the difference in the pressure applied to the control and challenged quarters (control - challenged quarter) increased by 1.1 +/- 0.4 kg of force 6 h after LPS infusion compared with the baseline, suggesting an increase in pain sensitivity in the challenged quarter. Neither the LPS infusion nor the meloxicam treatment had an effect on daily rumination time. However, the rumination diurnal pattern on the day of LPS infusion showed an overall deviation from the baseline pattern. Cows spent less time ruminating in the hours following LPS infusion and more time ruminating later in the day. Meloxicam did not alter somatic cell score or dry matter intake. However, meloxicam-treated animals had less udder edema and a lower body temperature in the hours following LPS infusion compared with control animals In conclusion, pressure algometers and rumination loggers show promise as tools to detect mastitis and monitor recovery on farm. Further, meloxicam has a beneficial effect in relieving pain and decreasing udder edema and body temperature in LPS-induced clinical mastitis.