The aim of this study was to identify genomic regions associated with ultrasound measures using a single-step genome-wide association study. Four measurements are collected – rump (P8FT) and rib (RBFT) fat thickness, eye muscle area (EMA), and intramuscular fat content (IMF). In addition, two other characteristics are recorded during the measurement – weight at scanning (SCW) and scrotal circumference (SC) for bulls. GWAS was performed on measures collected from 2,500 live animals.