Ultrasound measurements of muscle depth were analyzed to determine if these traits could be used to increase the rate of genetic gain in breast meat yield (BMY). Two measurements of breast depth, one taken horizontally across both breast lobes and one parallel to the keel, were captured using ultrasound. Heritabilities of muscle depth traits ranged from 0.35 to 0.70. These values were greater than heritabilities of conformation scores, which ranged from 0.25 to 0.47 within sex and line. The ultrasound traits also showed strong genetic correlations to BMY, ranging from 0.43 to 0.75, indicating that selection, using ultrasound depth as a correlated information source, could result in improved BMY. Including each ultrasound trait in a linear regression model predicting BMY increased the proportion of variation explained by the models by 0.08 to 0.17, relative to using conformation score as the only in vivo estimate. Based on results from a simulated turkey breeding program with selection pressure only on BMY, the ultrasound measures could increase the accuracy of a selection index for BMY by 0.02 to 0.16. As a result, ultrasound technology has the potential to improve the rate of genetic gain in BMY in a breeding program.