【摘要】 本试验将柔嫩艾美尔球虫凤阳株通过鸡体传代筛选早熟株,传5代后,接种鸡只,观察早熟株的致病性。选择30只15日龄健康无球虫感染鸡随机分成3组(n=10)(Ⅰ、Ⅱ、Ⅲ组),Ⅰ、Ⅱ组分别口服接种等量(1×105个/只)经5代选育的早熟株和亲本株孢子化卵囊,Ⅲ组为不接种空白对照组,根据临床表现、成活率、饲料转化率、每克粪便中卵囊数(OPG)、病变指数等指标判断早熟株与亲本株致病性差异,以及与不感染对照组的差别来衡量选育结果。结果表明早熟株与亲本株、早熟株与对照组的成活率、饲料转化率、每克粪便中卵囊数、病变指数的差异不显著,说明了早熟株的致病性没有明显的降低,可能是选育代数过少所致。更多还原

【Abstract】 Fengyang strain of E. tenella was passaged to select precocity strain through chickens, which wereinfected after five generations to observe pathogencity of precocity strain .In this experiment ,thirty healthy chick-ens were randomly divided into three groups(Ⅰ,Ⅱ and Ⅲ):The first group and the second group were orallyinfected with sporulated oocysts of fifth generation precocity strain and parent strain respectively. The third groupwere not infected as control group. Based on clinical symptom, survival rate, feed convertion rate, OPG, patho-genic and parent strain, between precocity strain infected group and control group can be revealed to judge theresult of cultivation. The results indicated that there was no difference between precocity strain group and parentstrain group, between precocity strain infected group and control group in survival rate, feed convertion rate ,OPG, pathogenic induce. It is suggested that pathogencity of precocity strain did not weaken dramatically, andcausing may probably be too few generations.更多还原