A system for measuring intramuscular fat in live cattle uses an ultrasound device to produce ultrasound image of an interior muscle portion. The image contains speckle caused by the scattering of ultrasound waves by the intramuscular fat. Image data representative of the speckle are analyzed in terms of pixel grey areas in the computer to produce measures of intramuscular fat including partial autocorrelation, correlation in a co-occurrence matrix and nonspeckle area.