A systematic review and network meta-analysis were conducted to assess the relative efficacy of internal or external teat sealants given at dry-off in dairy cattle. Controlled trials were eligible if they assessed the use of internal or external teat sealants, with or without concurrent antimicrobial therapy, compared to no treatment or an alternative treatment, and measured one or more of the following outcomes: incidence of intramammary infection (IMI) at calving, IMI during the first 30 days in milk (DIM), or clinical mastitis during the first 30 DIM. Risk of bias was based on the Cochrane Risk of Bias 2.0 tool with modified signaling questions. From 2280 initially identified records, 32 trials had data extracted for one or more outcomes. Network meta-analysis was conducted for IMI at calving. Use of an internal teat sealant (bismuth subnitrate) significantly reduced the risk of new IMI at calving compared to non-treated controls (RR = 0.36, 95% CI 0.25–0.72). For comparisons between antimicrobial and teat sealant groups, concerns regarding precision were seen. Synthesis of the primary research identified important challenges related to the comparability of outcomes, replication and connection of interventions, and quality of reporting of study conduct.

中文翻译：

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产前给予乳头密封剂预防乳房内感染和临床乳腺炎的比较疗效：系统评价和网络荟萃分析

进行了系统评价和网络荟萃分析，以评估在奶牛干燥时给予的内部或外部乳头密封剂的相对功效。如果对照试验评估了内部或外部乳头密封剂的使用，有或没有同时进行抗菌治疗，与不治疗或替代治疗相比，并测量了以下一项或多项结果：乳房内感染 (IMI) 的发生率产犊、乳汁前 30 天的 IMI (DIM) 或前 30 DIM 的临床乳腺炎。偏倚风险基于 Cochrane Risk of Bias 2.0 工具和修改后的信号问题。从最初确定的 2280 条记录中，32 项试验提取了一项或多项结果的数据。对产犊时的 IMI 进行了网络荟萃分析。与未处理的对照组相比，使用内部乳头密封剂（次硝酸铋）显着降低了产犊时新 IMI 的风险（RR = 0.36, 95% CI 0.25–0.72）。对于抗菌剂组和乳头密封剂组之间的比较，我们发现了对精确度的担忧。初步研究的综合确定了与结果的可比性、干预措施的复制和联系以及研究行为报告的质量相关的重要挑战。