Zhu J J, Lillehoj H S, Allen P C, Yun C H, Pollock D, Sadjadi M, Emara M G
USDA, Agricultural Research Service, Live Stock and Poultry Science Institute, Immunology and Disease Resistance Laboratory, Beltsville, Maryland 20705, USA.
Poult Sci. 2000 May;79(5):619-25. doi: 10.1093/ps/79.5.619.
To determine an optimal dose for coccidial inoculation and to evaluate genetic resistance or susceptibility in individual chickens, broilers were inoculated with four different doses of Eimeria maxima oocysts. Body weight gain, fecal oocyst shedding, concentrations of plasma NO2- + NO3-, carotenoid, and interferon-gamma were measured at two different time periods postinfection. The results showed significant dose and sex effects on most parameters and interaction between dose and sex in some parameters. The dose effects were generally linear; however, some significant quadratic effects were also observed. The measurements from chickens inoculated with 10(4) oocysts displayed the highest correlation coefficients among oocyst shedding, body weight gain, and concentrations of carotenoid and NO2- + NO3-. An infection index, calculated from the correlated parameters, displayed high correlation coefficients with the parameters. The infection index may be a better parameter for evaluating individual genetic resistance against coccidial infection.
为确定球虫接种的最佳剂量并评估个体鸡的遗传抗性或易感性，给肉鸡接种了四种不同剂量的巨型艾美耳球虫卵囊。在感染后的两个不同时间段测量了体重增加、粪便卵囊排出量、血浆中NO2- + NO3-、类胡萝卜素和干扰素-γ的浓度。结果显示，大多数参数存在显著的剂量和性别效应，某些参数存在剂量和性别的相互作用。剂量效应通常呈线性；然而，也观察到了一些显著的二次效应。接种10(4)个卵囊的鸡的测量结果在卵囊排出量、体重增加以及类胡萝卜素和NO2- + NO3-浓度之间显示出最高的相关系数。根据相关参数计算出的感染指数与这些参数显示出高相关系数。感染指数可能是评估个体对球虫感染的遗传抗性的更好参数。
