Jäger Michael, Gauly Matthias, Bauer Christian, Failing Klaus, Erhardt Georg, Zahner Horst
Institute of Parasitology, Justus Liebig University Giessen, Rudolf-Buchheim-Strasse 2, 35392 Giessen, Germany.
Vet Parasitol. 2005 Aug 10;131(3-4):173-91. doi: 10.1016/j.vetpar.2005.05.014.
Prevalences and intensities of excretion of faecal stages of Giardia duodenalis, Cryptosporidium parvum, Eimeria spp., Strongyloides papillosus and strongyles were determined in a German upland area in German Angus (GA) and German Simmental (GS) suckler of beef cattle herds covering two winter housing periods and the grazing season between them. Influences of the housing systems applied (maintenance on deep litter with (DL+) and without run-out (DL--), on slatted floor (SF) or by winter run-out yarding (WO)), breed differences and genetic influences by the sire were determined by statistical analyses; levels of IgG antibodies to E. bovis antigen were measured by ELISA. G. duodenalis was observed with a maximum prevalence of 38% in 4 weeks old calves, a cumulative incidence of 58% 9 weeks after birth and with generally low intensities. C. parvum infections were relatively rare with cumulative incidences of 20--25% in week 5 after birth. Highest prevalences were associated with housing system DL-- and a long-lasting calving period. Cumulative incidence of Eimeria spp. was almost 100%. E. bovis predominated by far followed by E. ellipsoidalis/zuernii. Mean maximum intensity of 1000 OpG occurred in week 7 after birth. Up to an age of the calves of 7 weeks >75% of all oocysts belonged to E. bovis. Prevalences and excretion intensities were lowest under the housing conditions SF and WO. Maternal antibodies in calves to E. bovis antigen were directly and inversely correlated with mean OpG values in GA and GS calves, respectively. S. papillosus was common with a cumulative incidence of 53% 9 weeks after birth and occurred independent of the housing system. Mean strongyle egg prevalence was 50% with 50--100 EpG by means throughout the grazing season. Egg excretion intensity in the early months of grazings was correlated with the age of the calves at turnout to pasture. Under the conditions of housing system DL-- GA calves could better control S. papillosus infections than GS calves whereas the latter were generally more effective in controlling the protozoa. Results of ANCOVA suggest significant paternal influences on S. papillosus infections in both breeds and on the protozoal infections in GA calves. The former could be disclosed independent of the housing system whereas environmental factors played an important role in the latter cases.
在德国高地地区的德国安格斯（GA）和德国西门塔尔（GS）肉牛犊牛群中，测定了两个冬季圈养期以及其间放牧季节十二指肠贾第虫、微小隐孢子虫、艾美耳属球虫、乳头类圆线虫和圆线虫粪便阶段的排泄率和强度。通过统计分析确定了所采用的饲养系统（垫料深层饲养且有运动场（DL +）和无运动场（DL -）、板条地面（SF）或冬季运动场围栏（WO））、品种差异以及父系的遗传影响；通过酶联免疫吸附测定法（ELISA）测量牛艾美耳球虫抗原的IgG抗体水平。观察到十二指肠贾第虫在4周龄犊牛中的最高感染率为38%，出生后9周的累计发病率为58%，且感染强度一般较低。微小隐孢子虫感染相对较少，出生后第5周的累计发病率为20% - 25%。最高感染率与饲养系统DL -和较长的产犊期有关。艾美耳属球虫的累计发病率几乎为100%。牛艾美耳球虫占主导地位，其次是椭圆艾美耳球虫/祖氏艾美耳球虫。出生后第7周平均最大强度达到1000个卵囊/克粪便（OpG）。在犊牛7周龄之前，所有卵囊中有超过75%属于牛艾美耳球虫。在饲养条件SF和WO下，感染率和排泄强度最低。犊牛中针对牛艾美耳球虫抗原的母源抗体分别与GA和GS犊牛的平均OpG值呈正相关和负相关。乳头类圆线虫较为常见，出生后9周的累计发病率为53%，且其发生与饲养系统无关。圆线虫虫卵平均感染率为50%，在整个放牧季节平均每克粪便中有50 - 100个虫卵（EpG）。放牧初期的虫卵排泄强度与犊牛转入牧场时的年龄相关。在饲养系统DL -的条件下，GA犊牛比GS犊牛能更好地控制乳头类圆线虫感染，而后者在控制原生动物感染方面通常更有效。协方差分析（ANCOVA）结果表明，父系对两个品种的乳头类圆线虫感染以及GA犊牛的原生动物感染有显著影响。前者在与饲养系统无关的情况下即可显现，而在后者的情况下环境因素起重要作用。
