Impact of prenatal maternal nutrition and parental residual feed intake (RFI) on mRNA abundance of metabolic drivers of growth and development in young Angus bulls

Abstract

• Muscular, hepatic, and testicular MEF2A expression associated with feed efficiency • Longissimus MEF2A expression was also affected by prenatal maternal nutrition • Hepatic PCDH19 expression was increased in bulls exposed to low prenatal nutrition • Muscular/hepatic/testicular gene expression correlated with measures of intake • Muscular/hepatic/testicular gene expression correlated with final/trimmed weight Approximately 70% of the cost of beef production is impacted by feed utilization. Maximizing production efficiency of beef cattle requires not only genetic selection to maximize feeding efficiency (i.e. residual feed intake - RFI), but also adequate nutrition throughout all stages of growth and development to maximize productivity of growth and reproductive capacity, even during gestation. Nutrient restriction during gestation has been shown to negatively affect post-natal growth and development. This, when combined with efforts to minimize RFI, may significantly affect energy partitioning in the offspring and subsequently important performance traits. Therefore, we decided to investigate the impacts of prenatal under-nutrition during the first half of gestation, as well as selection for divergent RFI, upon gene expression in select tissues, including Longissimus thoracis (LT) and semimembranosus (SM) muscles, liver, and testis, in Angus bull progeny. The genes monitored in this study included metabolic drivers of animal growth, especially muscle growth and development, and those that were aspects of detoxification/immune function. The results showed that the mRNA abundance of protocadherin 19 [ PCDH19 ] in liver, and myocyte enhancer factor 2A [ MEF2A ] in LT muscle, was significantly higher in Low-diet (Ldiet), and Normal-diet (Ndiet) prenatal maternal diet groups, respectively. The results also showed that in all four tissues, expression of MEF2A was significantly higher in the Low-RFI (LRFI) group as compared to its High-RFI (HRFI) counterpart. We also reported correlations between gene expression in these four tissues with phenotypic measures of feed efficiency and body weight.