Morton J M, Campbell P H
Department of Natural Resources and Environment, Warrnambool, Victoria.
Aust Vet J. 1997 Feb;75(2):109-13. doi: 10.1111/j.1751-0813.1997.tb14169.x.
To estimate the relative frequency of various disease signs in dairy cattle fed brassicas in south-eastern Australia, to estimate the incidence of disease signs within affected groups and to identify risk factors for commonly reported signs in brassica-fed dairy cows.
A case series study and a case-control study.
Case data was collected using an incident reporting system. Herd managers and veterinarians recorded details about disease incidents in brassica-fed dairy cattle in summer and autumn 1995 using a standard questionnaire. Potential risk factors for photosensitisation were assessed using a case-control study.
Disease signs were reported in 66 groups of brassicated dairy cattle. Photosensitisation and bloat were the more frequently reported signs. While high incidences were reported in some groups, the incidence of disease signs was low within most affected groups. Photosensitisation occurred more frequently among groups of cows fed brassica crops treated with nitrogenous fertilisers or which were low yielding. Risks of other disease signs were greatest while the first one quarter of the crop was grazed.
In the study population, most disease outbreaks occurring in brassica-fed cattle were of low incidence. However, some high incidence outbreaks occurred. Results from this study suggest that important risk factors exist for disease signs in brassica-fed dairy cattle. Further studies are required if these risk factors are to be fully identified. This would allow the development of preventative strategies for high incidence disease outbreaks while feeding brassicas to dairy cattle.
评估澳大利亚东南部饲喂芸苔属植物的奶牛各种疾病体征的相对频率，估计受影响群体中疾病体征的发生率，并确定饲喂芸苔属植物的奶牛常见体征的风险因素。
病例系列研究和病例对照研究。
使用事件报告系统收集病例数据。畜群管理者和兽医在1995年夏秋季节，使用标准问卷记录了饲喂芸苔属植物的奶牛疾病事件的详细情况。通过病例对照研究评估光敏反应的潜在风险因素。
在66组饲喂芸苔属植物的奶牛中报告了疾病体征。光敏反应和瘤胃胀大是报告较多的体征。虽然在一些群体中报告的发病率较高，但在大多数受影响群体中疾病体征的发生率较低。光敏反应在饲喂了氮肥处理的芸苔属作物或低产的奶牛群体中更频繁发生。在啃食作物的前四分之一期间，出现其他疾病体征的风险最大。
在研究群体中，饲喂芸苔属植物的奶牛发生的大多数疾病暴发发病率较低。然而，也出现了一些高发病率的暴发。本研究结果表明，饲喂芸苔属植物的奶牛出现疾病体征存在重要风险因素。如果要全面识别这些风险因素，还需要进一步研究。这将有助于制定在给奶牛饲喂芸苔属植物时预防高发病率疾病暴发的策略。
