Pulmonary arterial pressure (PAP) is a diagnostic measure used to determine an individual's susceptibility to developing high-altitude disease. The importance of PAP measures collected at elevations lower than the intended breeding elevation of the bulls (i.e., ≥1,520 m) is unknown. Therefore, the objective of this study was to determine the genetic relationship between PAP measures collected in a range of elevations using reaction norm models. A total of 9,177 PAP and elevation observations on purebred Angus cattle, which averaged 43.49 ± 11.32 mmHg and 1,878.6 ± 296.8 m, respectively, were used in the evaluation. The average age of the individuals in the evaluation was 434.04 ± 115.9 d. A random regression model containing the effects of sex, a linear covariate of age, a quadratic fixed covariate of elevation, and random effects consisting of a contemporary group and a linear regression of PAP on elevation was used for the evaluation of PAP. Two forms of PAP were evaluated with this model. First, to address the non-normality of the data, PAP was raised to the power of -2.6 (ptPAP) based on the results of a Box-Cox analysis. Second, raw PAP (rPAP) phenotypes were evaluated to compare the results to those obtained from the transformed data. For ptPAP, heritability ranged from 0.25 to 0.37 corresponding to elevations of 1,900 and 1,215 m, respectively. For rPAP, heritability ranged from 0.22 to 0.41 corresponding to elevations of 1,700 and 2,495 m, respectively. Generally, lower elevations corresponded to decreased heritabilities while higher elevations corresponded to increased heritability estimates. For ptPAP, genetic correlations ranged from 0.18 (elevation: 1,215 and 2,495 m) to 1.00. For rPAP, genetic correlations ranged from 0.08 (elevation: 1,215 and 2,495 m) to 1.00. In general, the closer the elevations in which PAP was measured, the greater the genetic relationship. The greater the difference in elevation between PAP measures resulted in lower genetic correlations. The rank correlation between expected progeny differences (EPD) for 1,215 and 2,495 m was 0.65 and 0.49 for the ptPAP and rPAP, respectively. These results suggested that PAP measures collected in lower elevations may be used as an indicator of high-altitude adaptability. In the estimation of EPD to rank sires for their suitability for use in high-elevation production systems, it is important to account for the relationships among varied altitudes.

中文翻译：

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使用安格斯牛中的反应规范模型评估肺动脉压对升高的敏感性。

肺动脉压（PAP）是一种诊断方法，用于确定个人对发展高海拔疾病的敏感性。在海拔低于公牛预期繁殖海拔（即≥1,520 m）的海拔高度上收集PAP措施的重要性尚不清楚。因此，本研究的目的是确定使用反应规范模型在一定高度范围内收集的PAP措施之间的遗传关系。在评估中，总共对纯种安格斯牛进行了9,177次PAP和海拔观测，平均分别为43.49±11.32 mmHg和1,878.6±296.8 m。评估中个体的平均年龄为434.04±115.9 d。一个随机回归模型，其中包含性别，年龄的线性协变量，海拔的二次固定协变量，由当代人群和PAP对海拔的线性回归组成的随机效应用于评估PAP。用此模型评估了两种形式的PAP。首先，为了解决数据的非正常性，基于Box-Cox分析的结果，将PAP的幂提高到-2.6（ptPAP）。第二，评估原始PAP（rPAP）表型，以将结果与从转化数据中获得的结果进行比较。对于ptPAP，遗传力范围从0.25到0.37，分别对应于1,900和1,215 m的海拔。对于rPAP，遗传力范围为0.22至0.41，分别对应于1700和2495 m的海拔。通常，较低的海拔高度对应于降低的遗传力，而较高的海拔高度对应于增加的遗传力估计。对于ptPAP，遗传相关性介于0之间。18（海拔：1,215和2,495 m）至1.00。对于rPAP，遗传相关性介于0.08（海拔：1,215和2,495 m）至1.00之间。通常，测量PAP的海拔越近，遗传关系就越大。PAP措施之间的海拔差异越大，遗传相关性越低。对于ptPAP和rPAP，1,215 m和2,495 m的预期子代差异（EPD）之间的等级相关性分别为0.65和0.49。这些结果表明，在较低海拔收集的PAP量度可以用作高海拔适应性的指标。在对EPD进行评估以对它们在高海拔生产系统中的适用性进行排名时，重要的是要考虑不同海拔之间的关系。遗传相关性从0.08（海拔：1,215和2,495 m）到1.00。通常，测量PAP的海拔越近，遗传关系就越大。PAP措施之间的海拔差异越大，导致遗传相关性越低。对于ptPAP和rPAP，1,215 m和2,495 m的预期子代差异（EPD）之间的等级相关性分别为0.65和0.49。这些结果表明，在较低海拔收集的PAP量度可以用作高海拔适应性的指标。在对EPD进行评估以对它们在高海拔生产系统中的适用性进行排名时，重要的是要考虑不同海拔之间的关系。遗传相关性从0.08（海拔：1,215和2,495 m）到1.00。通常，测量PAP的海拔越近，遗传关系就越大。PAP措施之间的海拔差异越大，遗传相关性越低。对于ptPAP和rPAP，1,215 m和2,495 m的预期子代差异（EPD）之间的等级相关性分别为0.65和0.49。这些结果表明，在较低海拔收集的PAP量度可以用作高海拔适应性的指标。在对EPD进行评估以对它们在高海拔生产系统中的适用性进行排名时，重要的是要考虑不同海拔之间的关系。遗传关系越大。PAP措施之间的海拔差异越大，遗传相关性越低。对于ptPAP和rPAP，1,215 m和2,495 m的预期子代差异（EPD）之间的等级相关性分别为0.65和0.49。这些结果表明，在较低海拔收集的PAP量度可以用作高海拔适应性的指标。在对EPD进行评估以对它们在高海拔生产系统中的适用性进行排名时，重要的是要考虑不同海拔之间的关系。遗传关系越大。PAP措施之间的海拔差异越大，遗传相关性越低。对于ptPAP和rPAP，1,215 m和2,495 m的预期子代差异（EPD）之间的等级相关性分别为0.65和0.49。这些结果表明，在较低海拔高度收集的PAP量度可以用作高海拔适应性的指标。在对EPD进行评估以对它们在高海拔生产系统中的适用性进行排名时，重要的是要考虑不同海拔之间的关系。分别。这些结果表明，在较低海拔收集的PAP量度可以用作高海拔适应性的指标。在对EPD进行评估以对它们在高海拔生产系统中的适用性进行排名时，重要的是要考虑不同海拔之间的关系。分别。这些结果表明，在较低海拔收集的PAP量度可以用作高海拔适应性的指标。在对EPD进行评估以对它们在高海拔生产系统中的适用性进行排名时，重要的是要考虑不同海拔之间的关系。