The mRNA expression of neuropeptides, (A) neuropeptide-Y (NPY), (B) agouti-related protein (AGRP), (C) Pro-opiomelanocortin (POMC), and (D) relaxin-3 (RLN3) in the arcuate nucleus of steers identified as low Residual Feed Intake (RFI) or high RFI. Expression was determined by real-time RT-PCR. Values were normalized to eukaryotic translation initiation factor 3 subunit K (EIF3K) expression. Data are expressed as fold change relative to High RFI steers and calculated according to Pfaffl (2010). Bars denoted by * differ (P < 0.05), Low, n = 8, High, n = 6.