Department of Animal Science, University of Minnesota, St. Paul 55108, USA.
J Dairy Sci. 2010 Apr;93(4):1729-35. doi: 10.3168/jds.2009-2625.
The objective of this study was to estimate genetic parameters of antibody response to Mycobacterium avium ssp. paratuberculosis using routinely collected Minnesota Dairy Herd Improvement milk ELISA tests. After all edits, 25,809 tests from 21,514 Holstein cows in 282 Johne's positive herds were available for analysis. The Johne's test results were analyzed both as a binary trait (positive or negative) and as a linear trait as the transformed ELISA optical density [ln(OD)]. Significant fixed effects in the model were age at test date, days in milk, and laboratory negative control; random effects were herd test date, animal effect, and permanent environment effect. Transformed ELISA optical density increased with age at test day and days in milk. Heritability estimates ranged from 0.065 to 0.095. Percentage of variation explained by maternal effects ranged from 1.3 to 2.29%. Repeatabilities ranged from 0.380 to 0.433. Statistically significant correlations between the sire solutions for ln(OD) for 154 bulls with at least 30 daughters in the analysis and their USDA predicted transmitting abilities were as follows: fat yield, -0.199; protein yield, -0.179; productive life, -0.292; and Net Merit, -0.339. These correlations suggest that selection for productive life or Net Merit also will improve resistance to Johne's disease.
本研究旨在利用常规收集的明尼苏达奶牛场改良牛奶 ELISA 测试来估计对分枝杆菌副结核亚种的抗体反应的遗传参数。在进行所有编辑后，可分析来自 282 个约翰氏病阳性牛群的 21514 头荷斯坦奶牛的 25809 次测试。约翰氏病测试结果既作为二元性状（阳性或阴性）进行分析，也作为线性性状（ln（OD）的转化 ELISA 光密度进行分析。模型中的固定效应包括测试日期的年龄、泌乳天数和实验室阴性对照；随机效应包括牛群测试日期、动物效应和永久环境效应。转化的 ELISA 光密度随测试日年龄和泌乳天数的增加而增加。遗传力估计值在 0.065 到 0.095 之间。母体效应解释的变异百分比范围在 1.3 到 2.29%之间。重复率在 0.380 到 0.433 之间。在分析中至少有 30 头女儿的 154 头公牛的 ln（OD）的 sire 解决方案与其 USDA 预测的传递能力之间存在统计学上显著的相关性，如下所示：脂肪产量，-0.199；蛋白质产量，-0.179；生产寿命，-0.292；和净效益，-0.339。这些相关性表明，对生产寿命或净效益的选择也将提高对约翰氏病的抗性。
