Thus far, there have been many studies focusing on meat quality improvement for Hanwoo (Korean cattle). It is considered that studies on meat quality have been actively conducted because beef consumption has changed from quantity to quality since early 1990's. Moreover, many studies on meat quality using maker assisted selection (MAS) have been conducted. However, there is a need to study quantity of meat in order to enhance the economic effect by genetic diversity and quantity of meat for Hanwoo. Therefore, in order to use a myostatin gene affecting meat quantity among quantitative genes for MAS, this study analyzed the association between genetic variation of myostatin gene in individuals of Hanwoo and carcass traits. Analysis between genotypes and individual phenotypic characteristics was performed by ANOVA using ASREML. Association analysis between these 10 SNPs and phenotypic characteristics (carcass weight, eye muscle area, backfat thickness, marbling score, yield index), and there were significant differences in 5 SNPs. As a result, there were five significant differences. Although all the SNPs did not show significant differences in each trait in this study, some SNPs showed significant differences in each trait. The diversity of myostatin gene was found in Hanwoo.

The bovine fatty acid binding protein 4 and 5 (FABP4 and 5) is a major positional and physiological candidate gene for the bovine marbling and carcass weight. The aim of this study was to evaluate the association between economic traits of Korean cattle (Hanwoo) and genetic variation in fatty acid binding protein 4 and 5 (FABP4 and 5) genes within carcass/meat quality traits and the before/after of fatting in breed Hanwoo. Here, we characterized the nucleotide polymorphism of FABP4 and 5 in 86 cattle. We were detected the variability of three types (GG, AG, and AA) by PCR, and economic traits were analyzed by the mixed regression model implemented in the ASReml program. As the result of statistical and supersonic analysis, FABP4 gene was highly showed significant effect (p<0.006) on marbling score (MS), in contrast FABP5 gene was lowed (p<0.084) on MS before fatting. But, FABP4 gene was highly showed significant effect (p<0.0054) on MS, in contrast FABP5 gene lowest (p<0.0899) on MS in the after of fatting. Compare to supersonic result before fatting in FABP4 gene, it was detected type GG: (p<7.18), AG: (p<8.50), and AA: (p<10.50) (n=50), showed type GG: (p<4.88), AG: (p<2.33), and AA: (p<0.00) after weed out (n=20). Futhermore, it was detected type GG: (p<9.30), AG: (p<7.95), and AA: (p<7.40) (n=50) before fatting in the FABP5 gene. It was shown type GG: (p<2.67), AG: (p<3.50), and AA: (p<5.00) after weed out (n=50). Our results indicate that FABP4 and 5 gene transcription is regulated by the environment of feeding and management, and suggest that feeding and management could be potential key in determining FABP4 and 5 genes transcription for carcass/meat quality traits in breed Hanwoo.