Development of Photographing Equipment for the Cross Section of Carcass and Prediction of BMS Number by Using Obtained Image from that Equipment

The first aim of this study was to develop photographing equipment, which is able to take a clear image of the cross section of carcass integrating the digital camera and the illumination device. The second aim was to predict the Beef Marbling Standard (BMS) number by using the obtained image from that equipment. The photographing equipment was composed of a dome section, a coaxial epi-illumination section, and a digital camera section. 570 white LEDs (Light Emitting Diode) were arranged upward at the bottom of the dome section like a ring. The half mirror of the 50% permeability was set up in a coaxial epi-illumination section at an angle of 45 degrees to the subject, and reflected light from the 324 white LEDs arranged on the side to the subject. The bottom of the dome section contacted with the cross section of carcass, so that photographing from a perpendicular direction and a constant distance was possible, Photographing for 271 Japanese Black cattle was executed with the developed equipment. As no sample with diffused reflection existed on the surface of the ribeye, clear and stable images were effectively taken by using this equipment. Multiple regression equation with the BMS number assigned by grader as the dependent variable were obtained by a stepwise method starting with 148 independent covariates for image analysis traits and some carcass traits. BMS number was predicted by using the multiple regression with six covariates selected by the stepwise method. The percentages of the difference between the assigned BMS and the predicted BMS being ±0 and within ±1 were 62.0% and 97.0%, respectively.