1997 Volume 68 Issue 12 Pages 1146-1153
Evaluation of beef marbling has been based on the Beef Marbling Standard (BMS) developed by the National Institute of Animal Industry, since 1988 in Japan. BMS number and marbling score were examined to determine which of them was more suitable scale for evaluation of beef marbling, considering the relationship between the scales and intramuscular fat area of the BMS measured by computer image analysis; and actual estimates for genetic and environmental variances, and heritability obtained using the two scales. Linear relationship was found between BMS number and ratio of intramuscular fat area to total rib-eye measured for the BMS, but not between marbling score and the ratio. The latter was rather positively quadratic. Further, when a larger number of the animals evaluated have over 10 on BMS number, the environmental variances for marbling score increased more than the genetic variances. The heritability for marbling score then became significantly lower compared to that for BMS number. As a conclusion, it is suggested that BMS number be a more suitable scale for evaluation of beef marbling than marbling score.
