An investigation of the efficacy of a polyvalent mastitis vaccine using different vaccination regimens under field conditions in the United King dom
An investigation of the efficacy of a polyvalent mastitis vaccine using different vaccination regimens under field conditions in the United King dom
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DOI：
10.3168/jds.2014-8332
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发表时间：
2015-03-01
影响因子：
3.5
通讯作者：
Green, M. J.
中科院分区：
文献类型：
--
作者：
Bradley, A. J.;Breen, J. E.;Green, M. J.
接种疫苗可以在乳房炎控制计划中发挥有用的作用，尽管相对缺乏大型的、控制良好的现场疗效研究。本文介绍了在英国现场条件下商业单位使用商业疫苗(Startwac，Hipra UK Ltd.，英国诺丁汉)的结果。总共从7个农场招募了3130头奶牛，并在农场内随机分配到3组中的1组。第一组按照标签方案接种疫苗，第二组在初始接种疗程后每隔90d接种一次，第三组不接种作为对照。在哺乳的前120天评估疫苗效果。1,549头奶牛的1,696个哺乳期的数据可供分析。三个研究组总共发生了779例临床性乳房炎，我们发现三组中任何一组的临床性或亚临床性乳房炎的发病率或患病率没有显著差异。接种LABEL方案后的乳房炎疫苗与显著降低临床病例的严重程度有关。这组奶牛患临床性乳房炎的几率显著降低，出现的不仅仅是牛奶变化[优势比：0.58；95%可信区间(CI)：0.35-0.98]。同样，每多接种一次疫苗，奶牛患临床性乳房炎的几率就会降低，出现的不仅仅是牛奶的变化(优势比：0.87；95%CI：0.77-0.98)。虽然在两个接种组中都没有奶牛因为严重的乳房炎而被扑杀，但我们发现两组之间与乳房炎相关的淘汰率没有显著差异。对产奶量数据的分析表明，平均而言，与未接种疫苗的奶牛相比，标签方案的奶牛在哺乳期的前120d产生了更多的乳量(231·L；95%可信区间：104.1-357.4)和更多的乳固形物(12.36千克；95%可信区间：3.12-21.60)。保守的分析表明，仅基于牛奶产量的增加，在英国的条件下，投资回报可以预期为2.57：1。
Vaccination can play a useful role in mastitis control programs, although there is a relative dearth of large, well-controlled field efficacy studies. This paper presents the findings on the use of a commercially available vaccine (Startvac, Hipra UK Ltd., Nottingham, UK) on commercial units under UK field conditions. In total, 3,130 cows were recruited from 7 farms and were randomly allocated, within farm, to 1 of 3 groups. The first group received the vaccine following the label regimen, the second group was vaccinated every 90 d following an initial vaccination course, and the third group was left unvaccinated to act as controls. Vaccine efficacy was assessed in the first 120 d of lactation. Data were available for analysis from 1,696 lactations in 1,549 cows. In total, 779 cases of clinical mastitis occurred in the 3 study groups, and we detected no significant difference in the incidence or prevalence of clinical or subclinical mastitis between any of the 3 groups. Mastitis vaccination following the label regimen was associated with a significant reduction in the severity of clinical cases. Cows in this group were at significantly decreased odds of developing clinical mastitis presenting with more than just milk changes [odds ratio: 0.58; 95% confidence interval (CI): 0.35-0.98]. Similarly, each additional vaccination resulted in a cow being at decreased odds of developing clinical mastitis presenting with more than just milk changes (odds ratio: 0.87; 95% CI: 0.77-0.98). Although no cows were culled because of severe mastitis in either of the vaccinated groups, we detected no significant difference in the mastitis-related culling rate between groups. Analysis of milk production data demonstrated that, on average, cows on the label regimen produced a higher volume of milk (231 L; 95% CI: 104.1-357.4) and more milk solids (12.36 kg; 95% CI: 3.12-21.60) than unvaccinated cows in the first 120 d of lactation. Conservative analysis suggested that a return on investment of 2.57:1 could be expected under UK conditions based on increased milk yield alone.