Effects of monounsaturated fatty acids compositions of intermuscular fat on carcass price of Japanese Black cattle

<p>In recent years, the ratio of monounsaturated fatty acids to the total fatty acids (MUFA%) has attracted attention due to the positive correlation with the flavor of the beef meat. However, very little research has been done on the relationship between MUFA% and carcass prices. This study was designed to explain the environmental effect on MUFA% and the effect of MUFA% on carcass unit price of Japanese Black cattle. The data were obtained from cattle that were shipped to the market in Hokkaido from 2013 to 2020 in this study. Carcass traits and image analysis traits, which was marbling percentage, coarseness index and new fineness index taken of the 6-7th rib of the carcass, MUFA% classified in units of 5% (4grades : <55%, 55～60%<, 60～65%<, 65%≦) were used for analysis. Least square means of MUFA% in slaughter date had decreased year by year. Phenotypic correlation coefficients were calculated to determine the relationship among MUFA% and each trait, and BFS No. was the highest (0.20). Least square means of unit prices in MQ (meat quality grades) 2 to 4 rose in association with increasing of MUFA% level (MQ3 : P<0.01). On the other hand, only MQ5 showed a decrease in unit prices with higher MUFA% (P<0.01). Investigated appearance ratio of BMS No. in each MUFA% level in MQ5 showed BMS No. 8 and No. 12 were in the same range in less than MUFA55% level, whereas decreasing of the appearance ratio with the rise of BMS No. in moreover MUFA65% level was indicated (BMS No. 12 : P<0.01). In addition, all of average of BFS No. were increased in each BMS No. with increasing MUFA% level (BMS No. 8-11 : P<0.01, BMS No. 12 : P<0.05). In conclusion, carcass unit prices increased with higher MUFA% in range of MQ2-4, while in only MQ5 it decreased. There was the positive correlation between MUFA% and BFS No., thus fat color tends to get dark with increasing of MUFA%. According to these results, it is thought that it is difficult to be evaluated higher BMS No. in high-MUFA% level as a boundary with muscle and marbling is ambiguous. It needs to explore appropriate MUFA% from the point of view of carcass price.</p>