Novel ultrasound approach for measuring marbling in pork.

An ultrasound examination was done on the m. longissimus lumborum, between the 10th and the 11th thoracic vertebra, on two sides (inside and outside the thoracic cavity) of the left half-carcasses of 162 fatteners. The carcasses were classified for lean meat percentage using the SEUROP system. The R pig carcasses (47.7% lean) had the thickest backfat (30.6mm; P≤0.01) and the highest content of intramuscular fat (IMF=2.28%; P≤0.01). More artifacts-free images were collected from the inside compared to the outside of the pig carcasses (90.1% vs. 58.6%; P≤0.01). The percent of bright pixels (PBP) was the highest for the inside, for all the lean-meat-content classes (P≤0.01). The correlation between the PBP and the IMF was higher for the images of the inside compared to the outside (r=0.811; P=0.001 vs. r=0.523; P=0.009). The ultrasound images of the inside of the carcasses proved to be the most useful for making an assessment of the marbling.