PREDICTION OF CARCASS TRAITS USING LIVE ANIMAL ULTRASOUND

Research of real-time ultrasound technologies at Iowa State University (ISU) has focused on software and application systems for measuring the percentage of intramuscular fat (PIMF) in the longissimus dorsi muscle in both live beef cattle and in hot beef carcasses. The developed software has been licensed to a commercial marketing firm and has been used by ultrasound technicians in two different proficiency testing programs held at ISU. Relationships between prediction biases and standard errors of prediction (SEP) for PIMF with actual carcass measures are summarized in this paper using Spearman rank correlations. Reasonable genetic progress for the PIMF trait in beef cattle should be possible using this technology. Good technician-machine systems achieve SEP of less than 1%, rank correlations of greater than .7, and biases of less than .5%.</p