An Evaluation of Fat Content via Image Analysis of the Carcasses of Three Different Beef Steer Breeds

Abstract

The aim of this study was to evaluate the extent of fat deposition on the cross section of a dressed carcass via the automated morphometry of an image analyzer. Six Japanese Black (JB), six Japanese Shorthorn (JN) and three crossbred steers (F1) were used to compare the fat depositions under the same nutritional plan of concentrate diet. The image analysis was conducted by using the macrosystem of the image analyzer, a Leitz TAS plus, on color pictures of the cross section between the 5th and 6th rib of a cooled carcass. The mean percentage area of intermuscular fat was greater in JN and F₁ steers than in JB steers. No difference was detected in the amount of muscle between the three steer breeds. In contrast, the amount of intramuscular fat in the rib-eye muscle of JB steers was larger than that of JN and F1 steers, which indicates that the meat quality of JB steers was better than that of JN and F1 steers. Thus, it was demonstrated that the system was a useful tool for determining the content of intramuscular fat in the carcass.