Estimation of beef marbling in the Longissimus musclewith computer image analysis of ultrasonic pictures ofthe Iliocostalis muscle area

摘要

This study investigated an objective method for estimating beef marbling using ultrasonic images of the Iliocostalis muscleand the Lomgissimus muscle area sections. Thirty-one Japanese Black cattle steers were used in this study. The end of theleft side shoulder blade bone was scanned using an ultrasonic device. Ultrasonic images were captured of the Longissimusmuscle area and that around the Iliocostalis muscle area. Twenty items were measured in the two images using computerimage analysis software. The level of beef marbling was measured according to the Beef Marbling Standard (BMS) forcarcass grading, and the percentage of ether-extractable fat content in the Longissimus muscle (EE). The difference in thegray level between the Iliocostalis muscle and intermuscular fat (X10) was used to estimate the BMS and the EE, whichwere highly correlated (r2 = 67.72% and 61.30%). An equation was developed using four parameters from the twoultrasonic images, which could estimate the BMS (r2 = 85.88%). This equation could also estimate the EE (r2 = 68.98%).The equations used to estimate beef marbling were based on one to four parameters that included X10. Thus, ultrasonicimages of the Iliocostalis muscle area section are important for estimating beef marbling.