INVESTIGATIONS ON THE ACCURACY AND THE AP PLICATION OF ULTRASONIC MEASUREMENTS FOR PREDICTING CARCASS COMPOSITION ON LIVE CATTLE

Ultrasonic and live measurements were taken on 143 young bulls of the genotypes Blond d'Aquitaine x Braunvieh, Limousin x German black pied and German black pied by end of fattening period at days 375 and 470 o f age. By means of ultrasound the area of the M. long. dorsi on the 1( st) and 4(th) lumbar vertebrae, the depth of the M. biceps femoris and fat measures over the ramp were measured. From 45 bulls the left carc ass side was dissected according to commercial guidelines and the tiss ue composition was determined. Ultrasound imaging instruments are accu rate. The accuracy of the ultrasound instruments increases with an hig her age of the bulls, because of improved experience of the operators and the enlargement of the measured areas and depths. The additional i nformation gained by ultrasonic measurements to estimate the percentag e of carcass composition is limited and does not justify the expenditu re and effords. Ultrasonic measurements at a later date with more accu rate recording of the subcutaneous fat depth and the construction of s pecific regression equitation's might improve the results.