scholarly journals Evaluation of moderate to high elevation effects on pulmonary arterial pressure measures in Angus cattle1

2018 ◽  
Vol 96 (9) ◽  
pp. 3599-3605 ◽  
Author(s):  
Rachel C Pauling ◽  
Scott E Speidel ◽  
Milton G Thomas ◽  
Timothy N Holt ◽  
Richard M Enns
Keyword(s):  
Arterial Pressure ◽  
Pulmonary Arterial Pressure ◽  
High Elevation ◽  
Pulmonary Arterial

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 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.

PAF increases vascular permeability without increasing pulmonary arterial pressure in the rat

2001 ◽  
Vol 90 (1) ◽  
pp. 261-268 ◽  
Author(s):  
Leonardo C. Clavijo ◽  
Mary B. Carter ◽  
Paul J. Matheson ◽  
Mark A. Wilson ◽  
William B. Wead ◽  
...  
Keyword(s):  
Arterial Pressure ◽  
Pulmonary Edema ◽  
Pulmonary Arterial Pressure ◽  
Ex Vivo ◽  
Platelet Activating Factor ◽  
Microvascular Permeability ◽  
Blue Dye ◽  
E Coli ◽  
Pulmonary Arterial

In vivo pulmonary arterial catheterization was used to determine the mechanism by which platelet-activating factor (PAF) produces pulmonary edema in rats. PAF induces pulmonary edema by increasing pulmonary microvascular permeability (PMP) without changing the pulmonary pressure gradient. Rats were cannulated for measurement of pulmonary arterial pressure (Ppa) and mean arterial pressure. PMP was determined by using either in vivo fluorescent videomicroscopy or the ex vivo Evans blue dye technique. WEB 2086 was administered intravenously (IV) to antagonize specific PAF effects. Three experiments were performed: 1) IV PAF, 2) topical PAF, and 3) Escherichia coli bacteremia. IV PAF induced systemic hypotension with a decrease in Ppa. PMP increased after IV PAF in a dose-related manner. Topical PAF increased PMP but decreased Ppa only at high doses. Both PMP (88 ± 5%) and Ppa (50 ± 3%) increased during E. coli bacteremia. PAF-receptor blockade prevents changes in Ppa and PMP after both topical PAF and E. coli bacteremia. PAF, which has been shown to mediate pulmonary edema in prior studies, appears to act in the lung by primarily increasing microvascular permeability. The presence of PAF might be prerequisite for pulmonary vascular constriction during gram-negative bacteremia.

scholarly journals 275 Phenotypic relationships between heart score and feed efficiency, carcass, and pulmonary arterial pressure traits

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 204-205
Author(s):  
Kathryn R Heffernan ◽  
Scott Speidel ◽  
Milt Thomas ◽  
Mark Enns ◽  
Tim Holt
Keyword(s):  
Arterial Pressure ◽  
Feed Efficiency ◽  
Pulmonary Arterial Pressure ◽  
Carcass Traits ◽  
Multiple Linear Regression Model ◽  
Strong Relationship ◽  
Fixed Effect ◽  
Heart Score ◽  
Important Relationship ◽  
Pulmonary Arterial

Abstract Pulmonary hypertension (PH) can lead to premature mortality in fed cattle and is often called Feedlot Heart Disease (FHD). To date, pulmonary arterial pressure (PAP) has been the only indicator trait of PH that has been evaluated. The objective of this study was to evaluate relationships between heart score (using heart score as a phenotype for PH) and PAP, carcass, and feed efficiency traits in fattening Angus steers. Our hypothesis was that feed efficiency and carcass traits, along with PAP, would demonstrate a strong relationship with heart score. Feed efficiency, carcass, PAP and heart score data from 89 Black Angus steers from Colorado State University Beef Improvement Center were collected and used for this study. Evaluations were performed using a multiple linear regression model, which included heart score as a categorical fixed effect and age as a continuous fixed effect. Least Square Means, pairwise comparisons, and ANOVA tables were constructed per trait. PAP (P < 0.001) showed an important relationship to heart score and average dry matter (P < 0.10) intake approached importance to heart score. In general, feed efficiency and carcass traits decreased as heart score increased, but PAP was the only trait with a strong relationship to heart score (P < 0.05). This led us to reject our hypothesis.

Regional pulmonary blood flow during 96 hours of hypoxia in conscious sheep

1986 ◽  
Vol 61 (6) ◽  
pp. 2136-2143 ◽  
Author(s):  
D. C. Curran-Everett ◽  
K. McAndrews ◽  
J. A. Krasney
Keyword(s):  
Blood Flow ◽  
Arterial Pressure ◽  
Pulmonary Blood Flow ◽  
Pulmonary Arterial Pressure ◽  
Pressor Response ◽  
Superior Vena ◽  
Acute Hypoxia ◽  
Vena Cava ◽  
Normobaric Hypoxia ◽  
Pulmonary Arterial

The effects of acute hypoxia on regional pulmonary perfusion have been studied previously in anesthetized, artificially ventilated sheep (J. Appl. Physiol. 56: 338–342, 1984). That study indicated that a rise in pulmonary arterial pressure was associated with a shift of pulmonary blood flow toward dorsal (nondependent) areas of the lung. This study examined the relationship between the pulmonary arterial pressor response and regional pulmonary blood flow in five conscious, standing ewes during 96 h of normobaric hypoxia. The sheep were made hypoxic by N2 dilution in an environmental chamber [arterial O2 tension (PaO2) = 37–42 Torr, arterial CO2 tension (PaCO2) = 25–30 Torr]. Regional pulmonary blood flow was calculated by injecting 15-micron radiolabeled microspheres into the superior vena cava during normoxia and at 24-h intervals of hypoxia. Pulmonary arterial pressure increased from 12 Torr during normoxia to 19–22 Torr throughout hypoxia (alpha less than 0.049). Pulmonary blood flow, expressed as %QCO or ml X min-1 X g-1, did not shift among dorsal and ventral regions during hypoxia (alpha greater than 0.25); nor were there interlobar shifts of blood flow (alpha greater than 0.10). These data suggest that conscious, standing sheep do not demonstrate a shift in pulmonary blood flow during 96 h of normobaric hypoxia even though pulmonary arterial pressure rises 7–10 Torr. We question whether global hypoxic pulmonary vasoconstriction is, by itself, beneficial to the sheep.

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