Prediction of Carcass Lean Yield Traits From Live Animal Ultrasound Measurements Prediction of Carcass Lean Yield Traits From Live Animal Ultrasound Measurements J.P. Gibson, K. Nadarajah, C.A. Aker and R.O. Ball Background Ultrasound probes have been used for many years in Canada and elsewhere to measure backfat depth on live pigs for use in genetic evaluation programs. Apart from the equipment used, there is also the question of which are the best sites to take measurements, and whether measurements at different sites provide information about different aspects of carcass composition. Another issue is ease of use in the field.
Current probes are simple to use and require no interpretation of images.
Real time machines are slightly more complex to use and provide stored visual images that require detailed interpretation after scanning. Correct interpretation is particularly important with cross-sectional images where the correct location and angle to measure fat and muscle depth must be determined along with the area of the muscle. Longitudinal real-time measurements provide an image of fat and muscle depths between 10th and 15th ribs. Cross sectional scans at 3-4th last rib, last rib and loin were interpreted manually by three different interpreters over the course of the experiment. Only interpreter C interpreted the images from pigs which had shoulder and ham measurements.