Snyder D B, Current W L, Russek-Cohen E, Gorham S L, Mallinson E T, Marquardt W W, Savage P K
Virginia-Maryland Regional College of Veterinary Medicine, Grayson Research Laboratory, University of Maryland, College Park 20742.
Poult Sci. 1988 May;67(5):730-5. doi: 10.3382/ps.0670730.
Banked serum samples collected from an industry-wide serologic survey of eighteen Delmarva broiler flocks conducted in 1985 were evaluated for the presence of Cryptosporidium- specific antibodies in an indirect enzyme-linked immunosorbent assay (ELISA). Evaluation of sera collected at 49-days posthatch showed that 38% of the broiler flocks were serologically positive, whereas 50% of samples obtained from flocks at 63-days during an extended growout were positive. From a performance standpoint, the top nine flocks in the study were essentially negative at the 49-day sampling. In order to more firmly establish the serologic prevalence of Cryptosporidium in Delmarva broiler flocks, a second serologic survey was conducted early in 1987. In this study, an estimated 22% of the 454 broiler flocks sampled at approximately 49 days of age were positive for Cryptosporidium. The negative Cryptosporidium serology in the top 25% of these flocks was associated with better performance, but positive Cryptosporidium serology was not clearly correlated with poor performance. Remarkable differences between Cryptosporidium serologic exposure rates of the growout companies were observed, with some companies having exposure rates as high as 40%, and others rates of less than 3%.
对1985年从德尔马瓦半岛18个肉鸡群进行的全行业血清学调查中收集的库存血清样本，采用间接酶联免疫吸附测定（ELISA）评估隐孢子虫特异性抗体的存在情况。对孵化后49天采集的血清进行评估发现，38%的肉鸡群血清学呈阳性，而在延长饲养期63天时从鸡群中采集的样本有50%呈阳性。从生产性能角度来看，研究中排名前九的鸡群在49天采样时基本呈阴性。为了更确切地确定德尔马瓦半岛肉鸡群中隐孢子虫的血清学流行率，1987年初进行了第二次血清学调查。在这项研究中，对约49日龄的454个肉鸡群进行采样，估计有22%对隐孢子虫呈阳性。这些鸡群中排名前25%的鸡群隐孢子虫血清学阴性与更好的生产性能相关，但隐孢子虫血清学阳性与生产性能差并没有明显关联。观察到不同饲养公司的隐孢子虫血清学暴露率存在显著差异，一些公司的暴露率高达40%，而其他公司则低于3%。
