Department of Animal Sciences, Colorado State University Fort Collins, CO 80523, USA.
Department of Animal Sciences, Texas A&M AgriLife Research, Beeville, TX 78102, USA.
J Anim Sci. 2023 Jan 3;101. doi: 10.1093/jas/skad288.
Pulmonary arterial pressure (PAP) can be used as an indicator of susceptibility to pulmonary hypertension and subsequent potential to develop right-sided heart failure (RHF). Previously reported heritability estimates of PAP have been moderate to high. Based on these estimates, selection for the indicator trait, PAP, could reduce the incidence of RHF due to hypoxia. Previous studies have also speculated that increased growth rates and body fat accumulation contribute to increased PAP and RHF. Research evaluating the genetic relationships between PAP and performance traits (e.g., yearling weight and postweaning gain) has yielded conflicting results, leading to ambiguity and uncertainty regarding the underlying genetic relationships. Additionally, no previous research has evaluated the relationship between PAP and ultrasound carcass traits. Therefore, the objective of this study was to estimate trait heritabilities and genetic correlations between PAP, post-weaning growth traits, and ultrasound carcass traits in Angus cattle, using data (n = 4,511) from the American Angus Association. We hypothesized that traits associated with increased growth and muscle would have a positive genetic (i.e., unfavorable) relationship with PAP. Estimates for heritability and genetic correlations were obtained using a multi-trait animal model. Heritability estimates for PAP (0.21 ± 0.04), post-weaning gain (PWG; 0.31 ± 0.04), and yearling weight (YWT; 0.37 ± 0.04) were within the range of estimates previously reported. Genetic correlations were weak (< 0.20) between PAP, PWG, and YWT. A low-to-moderate genetic correlation between PAP and ultrasound ribeye area (UREA) was found (0.25 ± 0.12). Genetic correlations between PAP, ultrasound back fat (UBF), ultrasound intramuscular fat (IMF), and ultrasound rump fat (RUMP) were weak (ranging in magnitude from -0.05 to 0.10) and therefore, do not provide strong support for the hypothesis of an antagonistic relationship between PAP and carcass ultrasound traits, while heritability estimates for UBF (0.43 ± 0.05), UREA (0.31 ± 0.04), IMF (0.35 ± 0.04), and RUMP (0.47 ± 0.05) were in the range of previously reported values.
肺动脉压（PAP）可用作肺动脉高压易感性和随后发生右侧心力衰竭（RHF）的潜在指标。先前报道的 PAP 遗传力估计值为中度至高度。基于这些估计，选择指标特征 PAP 可降低由于缺氧引起的 RHF 发病率。先前的研究还推测，生长率和体脂积累的增加导致 PAP 和 RHF 的增加。评估 PAP 与性能特征（例如，一岁重和断奶后增重）之间遗传关系的研究得出了相互矛盾的结果，导致对潜在遗传关系存在歧义。此外，以前的研究没有评估 PAP 与超声胴体特征之间的关系。因此，本研究的目的是使用美国安格斯协会的数据（n = 4511），估计安格斯牛中 PAP、断奶后生长性状和超声胴体性状之间的性状遗传力和遗传相关。我们假设与生长和肌肉增加相关的性状与 PAP 具有正遗传（即不利）关系。使用多性状动物模型获得遗传力和遗传相关的估计值。PAP（0.21 ± 0.04）、断奶后增重（PWG；0.31 ± 0.04）和一岁重（YWT；0.37 ± 0.04）的遗传力估计值在先前报道的范围内。PAP、PWG 和 YWT 之间的遗传相关性较弱（<0.20）。发现 PAP 和超声肋眼面积（UREA）之间存在低到中度遗传相关性（0.25 ± 0.12）。PAP 与超声背膘（UBF）、超声肌内脂肪（IMF）和超声臀部脂肪（RUMP）之间的遗传相关性较弱（大小范围为-0.05 至 0.10），因此，无法为 PAP 和胴体超声性状之间的拮抗关系假设提供有力支持，而 UBF（0.43 ± 0.05）、UREA（0.31 ± 0.04）、IMF（0.35 ± 0.04）和 RUMP（0.47 ± 0.05）的遗传力估计值在先前报道的值范围内。
