Ultrasound Definitions

Rib Fat: An external fat measurement taken between the 12th and 13th ribs, measured in inches.

Rump Fat: An external measurement taken between the hooks and pins, measured in inches. The rump fat and the rib fat measurements are used to determine the overall external body fat.

Ribeye Area: Area of the longissimus muscle, measured in square inches. The trait is moderately to highly heritable and gives an indication of overall carcass muscling.

Intramuscular Fat (%IMF): Percentage of fat in the ribeye area muscle (similar to marbling). The field technician collects four images and the values generated by the interpreting software are averaged for an overall %IMF. Marbling directly contributes to beef palatability.