14 Effect of Pulmonary Arterial Pressure and Precipitation Interaction on Reproductive Performance in Angus Heifers in South Central Wyoming

Abstract Variable precipitation in the western United States impacts forage availability, potentially influencing fertility. Furthermore, producers located above 1,500 meters contend with high altitude disease (HAD) due to reduced atmospheric oxygen, resulting right sided heart failure. Pulmonary arterial pressure (PAP) score is an indicator trait of HAD. The physiological stress elevated PAP could compound environmental stress, such as variable precipitation. Thus, objective this study was investigate interaction and on beef heifer Data for were sourced from Colorado State University Beef Improvement Center (CSU-BIC; 1993-2019; n = 3,834; 2,150 2,411 m elevation) near Saratoga, Wyoming. Records included identification, birth year, yearling weight (YW), PAP, first service conception (FSC), overall pregnancy (HPG) sire. Precipitation data National Oceanic Atmospheric Administration. Three classifications created: cumulative breeding, weaning, weaning breeding. Initial models contained sources variation classification, YW a by classification response HPG FSC. Logistical regression executed followed analysis variance. Yearling predictor FSC (P < 0.01) while breeding 0.05). In general, not detected; however, tended predict 0.10). A favorable, positive relationship detected between (bi=0.00120 00120 0.00124; P 0.01). also existed (bi=0.2528, Those results suggested that increased during development period advantageous HPG. provided evidence suggest may interact influence success. we conclude appears success Angus heifers high-altitude production system.