Comparison of carcass composition among Japanese Black, Holstein and their crossbred steers fattening on farm

Carcass composition among Japanese Black, Holstein and their crossbreed (F1), by Holstein mated with Japanese Black sires, was compared by using carcass components of fattening steers collected at eight carcass processing factories. The least squares means of 14 retail cuts, total weights of retail cuts, trimmed fat and bones, and six carcass traits measured at 6th?7th rib section were used for the comparison and examined the expression of heterosis. The comparison was performed at the same level of left‐side carcass weight and under 10 mm fat cover on each retail cut. Japanese Black had the heaviest total weight of retail cuts, followed by F1 and then Holstein. By contrast, non‐edible parts, trimmed fat and bones, were heavier in the order of Holstein, F1 and Japanese Black. Of the retail cuts, so called higher‐priced cuts, such as Shoulder‐Chuck‐Roll, Tender‐Loin, Rib‐Chuck‐Roll, Strip‐Loin and Sirloin‐Butt surrounding the spinal column, were heavier in Japanese Black than Holstein. Although F1 showed intermediate values for almost all traits, Tender‐Loin, Rib‐Chuck‐Roll and Strip‐Loin of F1 were similar to those of Japanese Black rather than the mid‐parent averages. It reflects that at least the average parent heterosis of 2.3–4.3% might be expressed in these higher‐priced cuts. The classification of breeds was carried out by the canonical discriminant analysis using 20 carcass measurements. By the canonical variates, breeds can be effectively discriminated with misdiscrimination rate of 11.6%. When the comparison is made at the carcass weight constant, Japanese Black has characteristics for producing superior carcass quality as well as meat quality.