Forty-eight female pigs slaughter at 50, 60, 70, 80, 90, 100, 110 and 120 kg were used to determine commercial cut and of lean meat yields in pork carcass, with a view of the Longissimus muscle area and backfat thickness estimation by using the real-time ultrasound technology. Live ultrasonic measurements were taken for Longissimus muscle area and for backfat thickness and measures in the hot carcass were made, using optical Henessy equipment, to estimate the backfat thickness and Longissimus muscle depth. The regression equations to estimate the amount of muscle in the carcass obtained a R² between 0.97 and 0.99, with a residual standard deviation (RSD) between 0.27 and 0.73. The R² values for Longissimus muscle area obtained by ultrasound and for backfat thickness direct in the carcass, were 0.97 and 0.98, respectively, with a RSD of 3.07 and 3.13. The adjustment of the regression equations for ultrasound backfat tickness, for optical backfat tickness and for directly carcass backfat tickness measurement, presented R² of 0.99, 0.82, and 0.86, respectively, with a RSD of 2.39, 3.13, and 2.91. The fitted regression equations obtained by simple and multiple linear regressions from the dissection data set were precise to estimate commercial cuts and of lean meat of pork carcasses between 50 and 120 kg. The real-time ultrasonograph technology is accurate to estimate the Longissimus muscle area and backfat tickness in live animal.
backfat thickness; lean meat yield; loin eye area; meat cuts; multiple and simple equations
