Binder Park Zoo, Battle Creek, MI 49014, USA,
San Diego Zoo-Global, Escondido, CA 92027, USA.
J Zoo Wildl Med. 2019 Sep;50(3):627-633. doi: 10.1638/2018-0075.
Domestic and nondomestic ruminant neonates with failure of passive transfer of immunity (FPI) have an increased risk of morbidity and mortality. Hand-reared individuals often have a higher incidence of FPI compared with those that are dam-reared. Hand-reared, nondomestic ruminant neonates raised at zoological establishments are often fed a commercially available bovine colostrum replacer. Consequently, it is desirable to monitor for FPI using a single test that performs well across a wide range of species. The immunocrit test method has been reported to have acceptable diagnostic sensitivity for detecting FPI in dairy calves. Advantages of the immunocrit are that it is inexpensive, quick, easy to perform, non-species-specific, and only precipitates immunoglobulins. This study evaluated the ability of immunocrit to predict serum immunoglobulin levels and FPI via comparison with radial immunodiffusion (reference method). The study used 100 serum samples collected from hand-reared ruminant neonates from 29 nondomestic species, 12-120 hr old, that were fed a commercial bovine colostrum replacer at a zoological institution. Sensitivity, specificity, and likelihood ratios for FPI were determined using receiver operating characteristic (ROC) curves. The immunocrit cutoff point of 14% maximized sensitivity at 88.6% (95% CI, 78.7-94.9%) and specificity at 83.3% (95% CI, 65.3-94.4%). The area under the ROC curve was 0.92 (95% CI, 0.87-0.98; < 0.001). This research demonstrates that the immunocrit test has acceptable performance in detecting FPI in a wide variety of nondomestic hand-reared ruminant neonates. Use of the immunocrit test will help improve the identification of FPI neonates and aid in the management of colostrum feeding practices of nondomestic ruminant species in captivity.
国内和非国内反刍动物新生动物若存在免疫被动转移失败（FPI），则其发病率和死亡率会增加。与经母畜喂养的动物相比，人工喂养的动物通常具有更高的 FPI 发生率。在动物园饲养的人工喂养的非国内反刍动物新生动物通常喂食市售的牛初乳替代品。因此，使用一种能够在广泛的物种中表现良好的单一测试来监测 FPI 是很有必要的。免疫 Crit 测试方法已被报道在检测奶牛幼畜的 FPI 方面具有可接受的诊断敏感性。免疫 Crit 的优点是价格低廉、快速、易于操作、非特异性且仅沉淀免疫球蛋白。本研究通过与放射免疫扩散（参考方法）比较，评估了免疫 Crit 预测血清免疫球蛋白水平和 FPI 的能力。该研究使用了 100 份来自 29 种非国内物种的 12-120 小时龄的人工喂养反刍动物新生动物的血清样本，这些动物在一家动物园机构中喂食市售的牛初乳替代品。使用接收者操作特征（ROC）曲线确定 FPI 的灵敏度、特异性和似然比。免疫 Crit 的截断值为 14%，可使灵敏度最大化，达到 88.6%（95%CI，78.7-94.9%），特异性为 83.3%（95%CI，65.3-94.4%）。ROC 曲线下面积为 0.92（95%CI，0.87-0.98；<0.001）。这项研究表明，免疫 crit 测试在检测各种非国内人工喂养的反刍动物新生动物的 FPI 方面具有可接受的性能。免疫 crit 测试的使用将有助于提高对 FPI 新生动物的识别，并有助于管理圈养非反刍动物的初乳喂养实践。
