Factors affecting the incidence rate of beef carcass defect 'Shikori'

The incidence rate of beef carcass defect 'Shikori' in the meat wholesale markets was investigated. The data of three breeds (n=149,288) ; Japanese Black, crossbred and dairy breed, were used. The incidence rates of 'Shikori' in the Japanese Black and crossbred were higher than in the dairy breed (P0.01), and have increased in recent years. The incidence rates of 'Shikori' were higher in KABURI and semispinalis muscle, and it did not always occur in both sides of the carcass. The significant differences in the incidence rates between meat quality grade, body weight (only in steers), marbling scores, age in month (only in steers), subcutaneous fat thickness (only in steers) were found in Japanese Black (P0.05 or P0.01). There were significant differences between body weight (P0.01) and subcutaneous fat thickness (P0.05) in crossbred steers and also between meat quality grade (P0.01), marbling score (P0.01), subcutaneous fat thickness (P0.05) in crossbred females. The effect of position in Japanese Black and crossbred was significant (P0.01). There were significant position x sex and position x breed interactions in Japanese Black and crossbred (P0.01). It was found that the higher the meat quality of Japanese Black and Crossbred (females), the thinner the subcutaneous fat of Japanese Black (steers) and crossbred the lower the body weight of Japanese Black and Crossbred, the higher the marbling score of females (Japanese Black and Crossbred), and the older the Japanese Black (steers) the higher were the incidence rates (P0.05 or P0.01). The incidence rate of 'Shikori' differed between farms. Results indicate that the incidence rate of 'Shikori' have increased in recent years and the increase is related to breed, sex, position, feedings and genetic factors.