Ultrasound back fat thickness
Phenotype
The ultrasound rib fat thickness measurement can be made from the same image used to estimate ribeye area. Fat thickness at the 12th-13th rib is measured at a point three fourths of the distance from the medial end of the longissimus dorsi muscle (12-13th rib interface) and perpendicular to the surface of the hanging ribbed carcass. Ultrasound scanning protocol requires the collection of an image made between the 12th-13thribs using a linear-array transducer and standoff guide that conforms to the curvature of the animal’s back
Adjusted Value
Ultrasonic back fat thickness is adjusted to a common age (e.g., 365 days of age) and in multi-breed settings is also adjusted for breed composition.
Contempory Group
Animals of the same sex, reared and managed together up until the time of scanning form a contemporary group. Scanning contemporary group definition includes the following: herd code, weaning date, weaning management group (pasture, creep, non-creep, etc.), scanning date, and post-weaning management group designation. For animals scanned at a central test, the contemporary group definition for an animal should include its herd of origin and other birth and weaning contemporary group information.