Machine and Technician Effect Ultrasonic Measures of Backfat and Loin Depth in Swine

North Carolina State University Swine Nutrition Research from 1998-2000. Ultrasonic measurement is routinely used for fat and muscle prediction in swine. One of the main reasons commercial producers currently have interest in the fat and lean composition of the live animal is because carcass value programs have become the predominant pricing system for marketing swine. Ultrasonic measures are also useful to determine lean gain patterns, select replacements, refine feeding programs and condition score sows. Much of the recent research with ultrasound has been conducted using brightness (B) mode instruments, with multi-element linear probes that produce two-dimensional cross-sectional images of the body. A-mode ultrasound machines generally use a single transducer in a single point estimation of depth. Therefore, B-mode ultrasound is currently considered the industry standard for live animal evaluation. However, A-mode ultrasonic equipment is generally less expensive, more durable and more portable than B-mode equipment. The objective of this study was to examine the accuracy of various A-mode ultrasound machines, as compared to B-mode ultrasound, for measurement of last rib backfat, tenth rib backfat and tenth rib loin muscle depth and to evaluate technician by machine interactions.