Experimental design used to estimate proportion of crows able to pass infectious RML scrapie prion (PrPRes) in feces (numbers of animals).

AMice intraperitoneally inoculated with gamma-irradiated crow fecal (CF) extract from crows gavaged with PrPRes (+) or control (−) mouse brain homogenate; additional control mice were inoculated with mouse-brain homogenate with (MB+) or without (MB−) PrPRes.BFive mice were randomly allocated to each crow and housed together in 1 cage postinoculation. Additional control mice were allocated randomly to MB treatment groups and 5 mice/treatment group were housed together in 1 cage postinoculation.A组小鼠经腹腔接种取自经灌胃给予抗蛋白酶朊蛋白（PrPRes）阳性（+）或阴性（-）小鼠脑匀浆的乌鸦的γ辐照乌鸦粪便（CF）提取物；另设置对照组小鼠，分别接种含PrPRes的小鼠脑匀浆（MB+）或不含PrPRes的小鼠脑匀浆（MB-）。B组：每只乌鸦对应分配5只小鼠，接种后同笼饲养；另有对照组小鼠被随机分配至MB处理组，每个处理组设置5只小鼠，接种后同笼饲养。