Ahola J K, Enns R M, Holt T
Department of Animal and Veterinary Science, University of Idaho, Caldwell Research and Extension Center, Caldwell, 83607, USA.
J Anim Sci. 2006 May;84(5):1259-64. doi: 10.2527/2006.8451259x.
Susceptibility of beef cattle to high altitude disease (HAD) is of major importance to economic and genetic selection on high elevation ranches. However, currently the best indicator of HAD susceptibility is the pulmonary arterial pressure (PAP) test, a test with high cost and invasive nature. Therefore, 2 experiments were undertaken to determine whether emerging technologies that predict blood components could be used to predict the PAP score in yearling Angus cattle. In Exp. 1, 39 yearling Angus bulls were used to determine if a relationship existed between PAP score and 10 blood components provided by a hemogram using whole blood or oxygen saturation as predicted by pulse oximetry in nonanesthetized cattle measured rectally or orally. Three of the hemogram values (packed cell volume, hemoglobin concentration, and red cell distribution width) were correlated (P < 0.10) with the PAP score. Prediction equations for PAP score were generated using the hemogram values and resulted in R2 values of 0.375 and 0.305 for the regression model using all of values and the best 2-variable model, respectively. Pulse oximetry was able to provide oxygen saturation predictions rectally or orally; however, the predicted values were not correlated with the PAP score (P > 0.10) or with each other (P > 0.10). In Exp. 2, 84 yearling Angus cattle (62 bulls, 22 heifers) were used to evaluate the ability of a portable clinical analyzer to predict the PAP score using 11 blood components from a sample of whole blood evaluated at the processing chute. The portable clinical analyzer was able to provide values for all of the 11 blood components; however, none of the predicted values were correlated with the PAP score (P > 0.10). In these preliminary experiments, 3 blood component values provided via the hemogram were the only variables both correlated with the PAP score and able to contribute to the development of a useful PAP prediction equation that could reduce the cost of traditional measures of HAD susceptibility. Future research is needed to determine whether additional blood components or emerging blood analysis technologies are able to accurately predict the PAP score in beef cattle.
肉牛对高原病（HAD）的易感性对于高海拔牧场的经济和遗传选择至关重要。然而，目前HAD易感性的最佳指标是肺动脉压（PAP）测试，该测试成本高昂且具有侵入性。因此，进行了两项实验，以确定预测血液成分的新兴技术是否可用于预测一岁安格斯牛的PAP评分。在实验1中，使用39头一岁安格斯公牛来确定PAP评分与通过全血细胞计数提供的10种血液成分之间是否存在关系，或者与通过直肠或口腔测量的非麻醉牛的脉搏血氧饱和度预测的血氧饱和度之间是否存在关系。全血细胞计数的三个值（血细胞比容、血红蛋白浓度和红细胞分布宽度）与PAP评分相关（P < 0.10）。使用全血细胞计数的值生成了PAP评分的预测方程，使用所有值的回归模型和最佳二变量模型的R2值分别为0.375和0.305。脉搏血氧饱和度能够经直肠或口腔提供血氧饱和度预测值；然而，预测值与PAP评分（P > 0.10）或彼此之间（P > 0.10）均无相关性。在实验2中，使用84头一岁安格斯牛（62头公牛，22头小母牛）来评估便携式临床分析仪使用在处理斜槽处评估的全血样本中的11种血液成分预测PAP评分的能力。便携式临床分析仪能够提供所有11种血液成分的值；然而，预测值与PAP评分均无相关性（P > 0.10）。在这些初步实验中，通过全血细胞计数提供的3个血液成分值是仅与PAP评分相关且能够有助于开发有用的PAP预测方程的变量，该方程可以降低传统HAD易感性测量方法的成本。需要进一步的研究来确定其他血液成分或新兴血液分析技术是否能够准确预测肉牛的PAP评分。
