Association between visual marbling score and chemical intramuscular fat with camera marbling percentage in Australian beef carcasses

Abstract

<p>This study assessed the precision and accuracy in the prediction of chemical intramuscular fat (IMF%), Meat Standards Australia (MSA) marbling score and AUS-MEAT eye-muscle area (EMA) using Meat Imaging Japan (MIJ) prototype camera systems. Eleven carcass datasets from the Beef Information Nucleus (BIN) project were compiled with carcass grading, IMF% and camera data. Camera prediction of IMF%, MSA marbling score and EMA was assessed using a leave-one-out cross validation method. There was an association between MIJ mirror and MIJ-30 camera traits and IMF%, MSA marbling score and EMA. However, for both prototypes precision varied for IMF% (R² = 0.4–0.5, RMSECV = 1.5–1.6%), MSA marbling (R² = 0.3–0.5, RMSECV = 57.5–59.3) and EMA (R² = 0.7–0.6, RMSECV = 4.1–5.8 cm² ). Accuracy also fluctuated with average bias values of 1.7–1.8%, 45.8–40.0 units and 3.8–4.1 cm² for IMF%, MSA marbling score and EMA respectively. Key differences between carcass and camera traits and processing factors affecting the grading site are likely to have contributed to this variation.</p>