Abstract:
The diagnosis of eimeriosis in calves mainly relies on the presence of diarrhoea and the excretion of Eimeria oocysts in the faeces. Restraining the animals to collect rectal samples for diagnostic purposes is stressful and time-consuming. The aim of this study was to evaluate a method for the quantification of oocysts in environmental barn straw samples. To investigate the recovery rate of the method, straw and Eimeria negative faeces were spiked with Eimeria oocysts in plastic bags and mixed with water and 0.05% Tween 20 (v/v); the liquids were filtered twice through sieves (mesh size 300 and 52 μm), centrifuged and the number of oocysts in the sediment determined using a McMaster counting chamber. A recovery rate of 52.4% (95% confidence interval: 48.2-56.5%) was obtained. In the following, field straw (n = 156) and individual faecal samples (n = 195, also analysed by McMaster counting chambers) were collected on four different farms. Eimeria oocysts were present on all farms in faecal (84/195, 43.1%) and straw samples (119/156, 76.3%). In 37 (23.7%) straw samples, sporulated oocysts were observed, with a sporulation rate ranging from 0 to 40%. Despite high variability between farms and examination days, mean numbers of oocysts in the straw positively correlated with mean numbers of oocysts excreted in the faeces (ρSpearman = 0.60). The examination of environmental straw samples may represent an easy-to-perform, non-invasive, inexpensive preliminary diagnostic approach for surveillance of eimeriosis at group level, having the potential to assess the infection pressure.
摘要:
小牛eimeriosis的诊断主要取决于腹泻的存在和粪便中艾美球虫卵囊的排泄。限制动物收集直肠样品用于诊断目的是有压力和耗时的。这项研究的目的是评估一种定量环境谷仓秸秆样品中卵囊的方法。为了研究该方法的回收率,将稻草和艾美球虫阴性粪便在塑料袋中掺入艾美球虫卵囊,并与水和0.05%Tween20(v/v)混合;通过筛子(筛目大小300和52μm)过滤两次液体,离心并使用McMaster计数室确定沉淀物中的卵囊数量。获得52.4%的回收率(95%置信区间:48.2-56.5%)。在下文中,在四个不同的农场收集了田间秸秆(n=156)和单个粪便样品(n=195,也由McMaster计数室分析)。艾美球虫卵囊存在于所有农场的粪便(84/195,43.1%)和秸秆样品(119/156,76.3%)中。在37份(23.7%)秸秆样品中,观察到有孢子的卵囊,孢子形成率从0到40%不等。尽管农场和考试日之间的差异很大,秸秆中卵囊的平均数量与粪便中排泄的卵囊的平均数量呈正相关(ρSpearman=0.60)。环境秸秆样品的检查可能是一种易于执行的,非侵入性,廉价的初步诊断方法,用于监测群体水平的Eimeriosis,有可能评估感染压力。