Petersen Mette Bisgaard, Ersbøll Annette Kjær, Krogh Kaspar, Nielsen Liza Rosenbaum
Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark.
National Institute of Public Health, University of Southern Denmark, Copenhagen, Denmark.
Prev Vet Med. 2019 May 1;166:86-92. doi: 10.1016/j.prevetmed.2019.03.013. Epub 2019 Mar 14.
Mycoplasma bovis infections cause disease and production losses in cattle worldwide. The long-term consequences are not well described despite being important for management decisions during and after disease outbreaks. We investigated the association between M. bovis antibody-positivity and undesired early departure (UED, i.e. death, euthanasia or slaughter) before first calving in a cohort of 636 heifers from 36 Danish dairy herds with and without a history of M. bovis-associated disease. The herds were visited 4 times at 3-month intervals and blood samples from young stock and milk samples from lactating cows were collected. Poisson regression was performed to examine the association with UED as outcome, logarithmic transformation of risk time as offset and herd as a random effect. Individual antibody measurements and group-level variables representing the infection level among young stock and cows, age and mortality variables were included in the model. The incidence rate ratio of UED increased by 1.23 times for every 10% increase in M. bovis young stock seroprevalence, while the effect of individual antibody level was modified by age and influenced UED less. In conclusion, UED in heifers was associated with M. bovis antibody-positivity in young stock and should be controlled in dairy herds to reduce losses.
牛支原体感染在全球范围内导致牛群发病和生产损失。尽管疾病爆发期间及之后的管理决策中，长期后果很重要，但目前对其描述并不充分。我们调查了来自36个丹麦奶牛场的636头小母牛组成的队列中，牛支原体抗体阳性与首次产犊前意外提前离场（UED，即死亡、安乐死或屠宰）之间的关联，这些奶牛场有或没有牛支原体相关疾病史。每隔3个月对这些牛场进行4次走访，并采集幼畜的血样和泌乳奶牛的奶样。采用泊松回归分析，以UED为结果变量，风险时间的对数转换作为偏移量，牛场作为随机效应，来检验两者之间的关联。模型中纳入了个体抗体测量值以及代表幼畜和奶牛感染水平、年龄和死亡率的组水平变量。牛支原体幼畜血清阳性率每增加10%，UED的发病率比增加1.23倍，而个体抗体水平的影响因年龄而异，对UED的影响较小。总之，小母牛的UED与幼畜牛支原体抗体阳性有关，奶牛场应加以控制以减少损失。
