Ribeye Area

Phenotype

Ribeye area is an indicator of muscling. The longissimus or ribeye muscle is measured at the 12th rib by using a grid or a ribeye tracing that is measured with a compensating polar planimeter or image analysis system.

Adjusted Value

Ribeye area is adjusted to an age constant.

Contemporary Group

A contemporary test group is a set of cattle of the same sex that have been raised together and have received equal treatment up to the point of slaughter. All progeny within a contemporary group should be born within a 90-day period, and male calves must be castrated prior to 150 days of age. A contemporary group up to the time of weaning will be subdivided if some cattle go on feed as calves and others are started on feed as yearlings, and if the cattle are then split into two or more slaughter groups. Birth date, identification of sire and dam, breed of dam (or breed proportions in crossbred dams) should be recorded for all individuals.

Genetic Evaluation

Carcass weight is generally included in a multi-trait model with traits such as ribeye area (carcass and ultrasound). Direct effects only are fitted.

Usage

Ribeye area contributes to the yield grade equation, but to a lesser degree than does back fat thickness. It is not an economically relevant trait but is an indicator of muscle and an indicator of the economically relevant traits complex of yield.