Backfat studies in growing pigs 2. A comparison of ultrasound and ruler probe predictors of backfat and eye-muscle measurements in the live pig

Abstract

ABSTRACT1. Three ultrasonic machines (Sonatest TE/6, Scanoprobe 731 and Scanogram 721) and the ruler probe were compared as techniques for estimating carcass introscope and caliper measurements of P2 backfat thickness on each of 96 pigs. The effect of operator experience was examined with the Sonatest and Scanoprobe machines. Scanogram measurements of P2 backfat and eye-muscle area were evaluated using two methods of restraint (crate and nose rope).2. The Sonatest was judged to be more precise (increased R2) than the Scanoprobe in predicting P2 backfat depth. Operator experience improved Scanoprobe precision but had little effect with the Sonatest. Ruler probe R2 was intermediate between the Sonatest and Scanoprobe.3. The Scanogram was the most precise live P2 backfat measurement technique. R2 was not affected by method of pig restraint.