The objective of this study was to determine if a phenotypic relationship between pulmonary arterial pressure (PAP) and oxygen consumption exists in beef cattle. Pulmonary arterial pressure is used as an indicator of pulmonary hypertension in cattle which is indicative of the susceptibility to both high-altitude disease and feedlot heart failure of an individual. Cattle with greater PAP are typically hypoxic and have initiated expression of compensatory mechanisms their cardio-pulmonary systems employ to combat this alveolar hypoxia. In turn, this causes an increase in PAP and, ultimately, right-sided heart failure. If hypoxic individuals consume more oxygen as a compensation mechanism, oxygen consumption as a trait could be used as an indicator of the prediction of PAP and feedlot heart failure and would be especially useful for cattle in deep phenotyping systems. Data used in the study included cattle with PAP measures on a total of 132 individuals. The data consisted of both steers (n = 99) and heifers (n = 33) from a ranch located in southern Wyoming at an elevation of approximately 2,195 m. After weaning on the ranch, cattle were transported to Colorado State University’s Agriculture Research, Development and Education Center located in Fort Collins, CO (elevation: 1,558 m). Oxygen consumption was measured using a Greenfeed system (C-Lock, Rapid City, South Dakota). To determine if a relationship exists between oxygen consumption and PAP, a simple linear regression model was used to regress PAP on average daily oxygen consumption. Effects included in the model were sex and phenotypic PAP. Average daily oxygen consumption was measured in kilograms per day and averaged 6.6 ± 1.66 kg with a range of 2.3 to 10.45 kg. Pulmonary arterial pressure averaged 42.6 ± 7.96 mm Hg and ranged from 33 to 81 mm Hg. In this data, sex did not account for a significant amount of variability in phenotypic PAP (P > 0.05). Oxygen consumption did account for a significant amount of variability in PAP (P < 0.05), and it was found that with every 1 kg increase of oxygen consumption, PAP is estimated to increase 1.02 mm Hg. These results indicate that a statistical relationship between oxygen consumption and PAP exists. Although these findings suggest that greater oxygen consumption leads to greater PAP, further research is required to fully comprehend the relationship between beef cattle PAP and oxygen consumption.

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343 肉牛肺动脉压表型与耗氧量的关系


本研究的目的是确定肉牛肺动脉压 （PAP） 与耗氧量之间是否存在表型关系。肺动脉压用作牛肺动脉高压的指标，它表明个体对高原病和饲养场心力衰竭的易感性。PAP 较大的牛通常是缺氧的，并且已经开始表达它们的心肺系统用来对抗这种肺泡缺氧的代偿机制。反过来，这会导致 PAP 增加，并最终导致右心衰竭。如果缺氧个体消耗更多的氧气作为一种补偿机制，那么耗氧量作为一种性状可以用作预测 PAP 和饲养场心力衰竭的指标，并且对深表型系统中的牛特别有用。该研究中使用的数据包括总共 132 只个体的 PAP 测量牛。该数据包括来自怀俄明州南部海拔约 2,195 m 的牧场的公牛 （n = 99） 和小母牛 （n = 33）。在牧场断奶后，牛被运送到位于科罗拉多州柯林斯堡（海拔：1,558 米）的科罗拉多州立大学农业研究、发展和教育中心。使用 Greenfeed 系统（C-Lock，南达科他州拉皮德城）测量耗氧量。为了确定耗氧量和 PAP 之间是否存在关系，使用简单的线性回归模型对平均每日耗氧量的 PAP 进行回归。模型中包含的影响是性别和表型 PAP。平均每日耗氧量以每天公斤为单位，平均为 6.6 ± 1.66 公斤，范围为 2.3 至 10.45 公斤。肺动脉压平均为 42.6 ± 7。96 毫米汞柱，范围为 33 至 81 毫米汞柱。在该数据中，性别没有解释表型 PAP 的显着变异性 （P > 0.05）。耗氧量确实是 PAP 的显著可变性的原因 （P < 0.05），并且发现耗氧量每增加 1 kg，PAP 估计会增加 1.02 mm Hg。这些结果表明耗氧量和 PAP 之间存在统计关系。尽管这些发现表明更大的耗氧量会导致更大的 PAP，但需要进一步的研究来充分理解肉牛 PAP 与耗氧量之间的关系。