The prediction of pork carcass composition using live animal echographic measurements from the Krautkramer USK7, Ithaca Scanoprobe 731C and Aloka SSD-210DXII Echo Camera

Abstract

Live animal ultrasonic measurements of back fat depth and muscle depth were made on 130 Lacombe and 96 Yorkshire pigs within a weight range of 85.5–114.2 kg, using a Krautkramer USK7 (KK), an Ithaca Scanoprobe 731C (SC) and an Aloka SSD-210DXII Echo Camera (AEC), with an average carcass weight of 80.8 kg. Animals were assessed 1 d prior to slaughter at the mid-back and the loin site as specified by the Canadian Swine Improvement Program and the carcass grade site. Back fat depth measurements made by the SC, KK and AEC reduced the residual variance for lean yield by an additional 35, 43 and 45%, respectively, beyond adjusting for gender, breed and live weight. The mid-back site had less precision than the loin or grade sites for the prediction of both lean yield and fat yield, and there were no clear advantages for using the loin site in preference to the grade site. Since there are no easily identifiable landmarks for locating the grade site on the live pig, the loin site remains the preferred site for live animal evaluation. The addition of muscle-depth measurements to fat-depth measurements resulted in modest increases in the R2 (1–4%) in precision for the prediction of carcass composition. Differences in the ability of the KK and AEC to predict lean yield were small and, considering their cost, suggest that the application of real-time ultrasonics to live animal evaluation may not be practical at this time. Key words: Swine, ultrasound, lean yield, probe sites