PSI-6 - Early life programming of the bovine jejunum function in response to maternal vitamin and mineral supplementation

Abstract: Despite the increased appreciation of the involvement of maternal nutrition in fetal development, its effects on jejunum programming remain largely unexplored. Here, we investigated the impact of maternal vitamin and mineral supplementation throughout gestation on the differential gene expression and underlying biological pathways in the jejunum of neonatal calves. For this, beginning 60 d before breeding and continuing throughout gestation, crossbred Angus heifers (n = 14) were fed either a basal diet (CON; n = 7) or the basal diet plus 113 g•heifer^-1•d^-1 of VTM supplement (VTM; n = 7). All heifers were gestating female calves, which were euthanized 30 h after birth. Samples of jejunum mucosa were collected, stored at -80◦C, then subjected to total RNA isolation and RNA sequencing. After quality control, the reads were mapped using STAR aligner and differentially expressed genes (DEGs) were identified using DESeq2. Maternal VTM supplementation did not affect calf organ mass, including jejunum weight. However, high-resolution respirometry analysis revealed greater mitochondrial efficiency in jejunum of calves from VTM supplemented dams. Additionally, we identified 528 DEGs between the VTM and CON calves (p-value ≤ 0.05 and |log2FC| > 0.5). Among them, the genes IGFBP2 and IGFBP6, which are key genes in insulin pathway and involved in regulation of insulin-like growth factors, IGF transport, and uptake, were upregulated in the VTM group. Additional pathways were identified using ShinyGO, which included the pancreatic secretion pathway, over-represented by genes such as PLCB1, CCK, and SLC26A3. The gene PLCB1 has been associated with feed efficiency, growth, and carcass traits in multiple species. Likewise, the SLC26A3 gene encodes a key intestinal chloride anion exchanger associated with enhanced feed efficiency in cattle. Genes encoding signaling molecules involved with immune response, T cell activation, and defense response were also among the DEGs upregulated in the VTM calves, including the TNFSF18 and TNFRSF4 genes. Our findings suggest that maternal prenatal vitamin and mineral supplementation throughout gestation affects the expression of genes involved in the jejunum function of offspring at a neonatal time point. The long-term consequences of these changes, however, warrant further investigation.