scholarly journals 286 Gestation length as a weak predictor of yearling pulmonary arterial pressure and risk of developing high altitude disease in Angus cattle at high elevation.

2018 ◽  
Vol 96 (suppl_3) ◽  
pp. 106-107
Author(s):  
H Foxworthy ◽  
R Enns ◽  
S Speidel ◽  
M Thomas ◽  
T Holt
Keyword(s):  
Arterial Pressure ◽  
High Altitude ◽  
Pulmonary Arterial Pressure ◽  
High Elevation ◽  
Gestation Length ◽  
Angus Cattle ◽  
High Altitude Disease ◽  
Pulmonary Arterial

scholarly journals Evaluation of the sensitivity of pulmonary arterial pressure to elevation using a reaction norm model in Angus Cattle

2020 ◽  
Vol 98 (5) ◽  
Author(s):  
Scott E Speidel ◽  
Milton G Thomas ◽  
Timothy N Holt ◽  
R Mark Enns
Keyword(s):  
Arterial Pressure ◽  
High Altitude ◽  
Genetic Relationship ◽  
Pulmonary Arterial Pressure ◽  
Genetic Correlations ◽  
Reaction Norm ◽  
High Elevation ◽  
Random Regression ◽  
Angus Cattle ◽  
Pulmonary Arterial

Abstract 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.

scholarly journals 265 Evaluation of the genetic relationship amongst high elevation pulmonary arterial pressure, feedlot and carcass performance traits

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 197-197
Author(s):  
Emma A Briggs ◽  
Scott Speidel ◽  
Mark Enns ◽  
Milt Thomas ◽  
Tim Holt
Keyword(s):  
Arterial Pressure ◽  
Genetic Relationship ◽  
Feed Intake ◽  
Pulmonary Arterial Pressure ◽  
Carcass Traits ◽  
Genetic Correlations ◽  
High Elevation ◽  
Pulmonary Arterial ◽  
Carcass Performance ◽  
Moderate Elevation

Abstract The objective of the study was to evaluate if a genetic relationship exists between pulmonary arterial pressure (PAP) measured at high elevation with traits associated with moderate elevation feedlot and carcass traits. For this analysis, PAP, feed intake, and carcass data were taken from 6,898, 558, and 1,627 animals, respectively. At an elevation of 2,115 m, PAP measurements were collected, then a selective group of steers was relocated to a moderate elevation feedlot (1,500 m) where feed intake data were collected. Genetic relationships were evaluated with 5-trait animal models using REML statistical analysis. For all traits in the analysis, fixed effects and contemporary groups were assigned as well as a direct genetic random effect. For weaning weight, a maternal permanent environmental effect was applied in the analysis. For PAP, the heritability estimate was 0.29 ± 0.03. Genetic correlations between PAP with feedlot traits was positive, with estimates of 0.34 ± 0.20 (average dry matter intake) and 0.05 ± 17 (average daily gain). The strongest genetic correlation between PAP and carcass performance traits were those of rib eye area (-0.30 ± 0.12) and calculated yield grade (0.29 ± 0.13). Genetic correlations between PAP and marbling score, back fat, or hot carcass weight were 0.00 ± 0.13, -0.07 ± 0.13, and 0.14 ± 0.10, respectively. These results suggest a favorable genetic relationship exists between PAP with feedlot and carcass traits.

scholarly journals 283 Heterosis and its potential influence on pulmonary arterial pressure in beef cattle

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 208-209
Author(s):  
Roderick A Gonzalez Murray ◽  
Miguel A Sánchez-Castro ◽  
Milt Thomas ◽  
Scott Speidel ◽  
Mark Enns
Keyword(s):  
Arterial Pressure ◽  
Pulmonary Arterial Pressure ◽  
Pap Test ◽  
High Altitude Disease ◽  
General Average ◽  
Pulmonary Arterial ◽  
Red Angus ◽  
Available Information ◽  
High Elevations ◽  
Additive Genetic Effects

Abstract High altitude disease (HAD) is a hypoxia-influenced pathologic condition experienced by cattle raised at high elevations (> 1,524 m). Pulmonary arterial pressure (PAP) is a common diagnostic tool used as an indicator of susceptibility to develop HAD. Given PAP is moderately heritable, possibilities to genetically reduce the incidence of HAD are feasible. However, an alternative strategy could be given by heterosis, since non-additive genetic effects have been related to survivability and environmental fitness. Therefore, objectives of this study were to determine heterosis and breed percentage effects on PAP measurements. A total of 1,083 cattle with varying percentages of Simmental, Angus, Hereford and Red Angus breeds were used for the study. Such animals’ available information included PAP records, PAP test date, PAP technician, sex, herd of origin and breed percentages of parents. A general linear model was utilized to estimate the effect of heterosis on PAP. Contemporary group (defined as a combination between herd, PAP date, PAP technician and sex) was included as a categorical fixed effect; whereas the age at PAP measurement and the degree of outcross were included as linear covariates. Similarly, breed effects were estimated by including breed percentages of Simmental, Angus, Hereford, Red Angus and “Other” breeds as linear covariates in the model. The general average for PAP measurements in the entire dataset was 41.29 ± 0.22, with range of 26 and 108 mmHg. The estimated regression coefficient for PAP on heterosis was -1.834 ± 1.676 mmHg/percent of outcross (P = 0.276), whereas, the range of breed effects on PAP was 15.08 mmHg. These results suggested that heterosis had no significant effects on PAP measurements. However, further research including other multibreed populations is required in order to better understand if increased levels of heterozygosity could potentially be related to lower PAP scores.

scholarly journals Pulmonary arterial pressure at rest and during exercise in chronic mountain sickness: a meta-analysis

2019 ◽  
Vol 53 (6) ◽  
pp. 1802040 ◽  
Author(s):  
Rodrigo Soria ◽  
Matthias Egger ◽  
Urs Scherrer ◽  
Nicole Bender ◽  
Stefano F. Rimoldi
Keyword(s):  
Arterial Pressure ◽  
High Altitude ◽  
Pulmonary Arterial Pressure ◽  
Meta Analysis ◽  
Right Heart Failure ◽  
Exercise Intolerance ◽  
Point Estimate ◽  
Chronic Mountain Sickness ◽  
Pulmonary Arterial ◽  
Mountain Sickness

Up to 10% of the more than 140 million high-altitude dwellers worldwide suffer from chronic mountain sickness (CMS). Patients suffering from this debilitating problem often display increased pulmonary arterial pressure (PAP), which may contribute to exercise intolerance and right heart failure. However, there is little information on the usual PAP in these patients.We systematically reviewed and meta-analysed all data published in English or Spanish until June 2018 on echocardiographic estimations of PAP at rest and during mild exercise in CMS patients.Nine studies comprising 287 participants fulfilled the inclusion criteria. At rest, the point estimate from meta-analysis of the mean systolic PAP was 27.9 mmHg (95% CI 26.3–29.6 mmHg). These values are 11% (+2.7 mmHg) higher than those previously meta-analysed in apparently healthy high-altitude dwellers. During mild exercise (50 W) the difference in mean systolic PAP between patients and high-altitude dwellers was markedly more accentuated (48.3 versus 36.3 mmHg) than at rest.These findings indicate that in patients with CMS PAP is moderately increased at rest, but markedly increased during mild exercise, which will be common with activities of daily living.

scholarly journals Assessment of right atrial dyssynchrony by 2D speckle-tracking in healthy young men following high altitude exposure at 4100 m

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0247107
Author(s):  
Chunyan He ◽  
Hedong Xiang ◽  
Chuan Liu ◽  
Shiyong Yu ◽  
Jie Yang ◽  
...  
Keyword(s):  
Arterial Pressure ◽  
High Altitude ◽  
Speckle Tracking ◽  
Pulmonary Arterial Pressure ◽  
Young Men ◽  
Right Atrial ◽  
Peak Strain ◽  
Altitude Exposure ◽  
2D Speckle Tracking ◽  
Pulmonary Arterial

Background High altitude exposure induces overload of right-sided heart and may further predispose to supraventricular arrhythmia. It has been reported that atrial mechanical dyssynchrony is associated with atrial arrhythmia. Whether high altitude exposure causes higher right atrial (RA) dyssynchrony is still unknown. The aim of study was to investigate the effect of high altitude exposure on right atrial mechanical synchrony. Methods In this study, 98 healthy young men underwent clinical examination and echocardiography at sea level (400 m) and high altitude (4100 m) after an ascent within 7 days. RA dyssynchrony was defined as inhomogeneous timing to peak strain and strain rate using 2D speckle-tracking echocardiography. Results Following high altitude exposure, standard deviation of the time to peak strain (SD-TPS) [36.2 (24.5, 48.6) ms vs. 21.7 (12.9, 32.1) ms, p<0.001] and SD-TPS as percentage of R–R’ interval (4.6 ± 2.1% vs. 2.5 ± 1.8%, p<0.001) significantly increased. Additionally, subjects with higher SD-TPS (%) at high altitude presented decreased right ventricular global longitudinal strain and RA active emptying fraction, but increased RA minimal volume index, which were not observed in lower group. Multivariable analysis showed that mean pulmonary arterial pressure and tricuspid E/A were independently associated with SD-TPS (%) at high altitude. Conclusion Our data for the first time demonstrated that high altitude exposure causes RA dyssynchrony in healthy young men, which may be secondary to increased pulmonary arterial pressure. In addition, subjects with higher RA dyssynchrony presented worse RA contractile function and right ventricular performance.

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