Relationship of Yearling Angus Bull Pulmonary Arterial Pressure Scores with Production, Maternal, and Carcass Expected Progeny Differences

Abstract

The objectives of this study were to model the relationship of PAP scores with production, maternal, and carcass (EPDs). Bull PAP scores were collected from 12–18-month-old Angus bull from a Montana-based Angus operation (>1600 m elevation, 5400 yearlings/18-month-old bulls from 2016–2023). Bulls with greater calving ease direct had lower PAP scores (p < 0.01; conditional r2 = 1.06%; marginal r2 = 0.62%). Bulls with greater birth weight EPDs had greater PAP scores (p < 0.01; conditional r2 = 1.15%; marginal r2 = 0.73%). Pulmonary arterial pressure was greater for bulls that had greater weaning weight EPDs (p < 0.01; conditional r2 = 0.82%; marginal r2 = 0.16%) and for bulls that had greater yearling weight EPDs (p < 0.01; conditional r2 =0.93%; marginal r2 = 0.24%). Bulls with greater PAP had greater carcass weight EPDs (p = 0.03; conditional r2 = 0.69%; marginal r2 = 0.18%). There were no observed relationships (p ≥ 0.17) between bull PAP and scrotal circumference, maternal milk, ribeye area, or marbling EPDs. In summary, PAP was related to calving ease direct, birth weight, weaning weight, yearling weight, and carcass weight EPDs. However, these relationships explain very little of the variation of PAP scores.