본 연구는 한우의 성별에 따른 소분할 부위별 pH, 일반성분 및 육색을 조사하고자 한우 15두(암소 5두, 수소 5두 및 거세우 5두)를 도축한 다음 등급 판정을 한 후 39개 소분할 부위를 발골하여 육질 특성을 분석하였다. 소분할 부위별 pH는 5.52~6.25를 나타내었으며, 대체로 거세우에서 암소와 수소에 비해 높은 값을 나타내었다. 수분, 지방, 단백질 함량은 소분할 부위와 성별에 따른 유의적인 차이를 나타내었다(p<0.05). 수소와 거세우의 앞사태 부위에서 가장 높은 수분함량을 나타내었다(p<0.05). 지방함량은 거세우의 차돌박이 부위에서 가장 높았으며 다음으로 암소의 업진살, 암소, 수소 거세우의 본갈비 순이었다. 콜라겐함량은 암소와 거세우는 부위에 따른 유의적인 차이가 나타나지 않았다(p>0.05). 암소와 거세우의 차돌박이 부위는 높은 명도 값을 나타내었으며, 암소와 수소의 차돌박이 부위는 낮은 적색도 값을 나타내었다(p<0.05). 황색도는 암소, 수소 및 거세우의 차돌박이 부위에서 가장 높은 값을 나타내었다(p<0.05). 색도는 암소, 수소 및 거세우는 홍두깨살 부위에서 가장 높았으며, 암소와 거세우는 업진안살에서 가장 낮은 값을 나타내었다(p<0.05). 2등급 한우고기의 수분함량은 수소가 높고, 지방함량은 암소가 높으며, 거세우는 높은 pH 값과 낮은 명도 값을 나타내었다.

The objective of this study was to investigate the effects of dry-aging and wet-aging conditions on the chemical composition, meat quality traits (color, water holding capacity, cooking loss, WBSF and pH) and shelf-life TBARS (2-thiobarbituric acid reactive substances) and VBN (volatile basic nitrogen) of loin (M. longissimus thoracis), sirloin (M. glutaeusmedus) and top-round (M. semimembranosus) cuts of Hanwoo cows. The dry-aging condition (temperature ℃, relative humidity %) was done for 60 d as 2℃, 65％, 20 d＋2℃, 75％, 20 d＋4℃, 85％, 20 d while, the wet-aging was done for 60 d at 1℃, 85%. Results revealed that moisture content was significantly higher in the dry-aged samples than that of the wet-aged samples at 60 d (p<0.05). The a*- and b*-values were significantly higher in 3 cuts as compared with those treated with wet-aging condition. During the dry-aging time, the WHC significantly increased in the loin and sirloin and they were significantly higher than wet-aging condition at 40 d and 60 d (p<0.05). The WBSF values significantly decreased with increased aging time and there was no significant difference between two aging methods. The TBARS and VBN contents significantly increased with increased aging time for all the wet- and dry-aged cuts, and their levels still fell within the acceptable standard limit. Generally, the TBARS and VBN contents were significantly higher in the dry-aged cuts, probably due to the increased levels of protein and fatty acids oxidations. Based on the results obtained in the present study, it can be suggested that application of dry-aging method can improve the quality characteristics of beef.

These studies were conducted to evaluate developmental competence of follicular oocyte collected from the ovaries of Hanwoo cows with the high offspring meat quality (1++ and 1+ grade). Cumulus oocyte complexes from individual cows were matured, fertilized and cultured using protocols of in-vitro maturation (IVM), in-vitro fertilization (IVF) and in-vitro culture (IVC). The rates of blastocyst development from Hanwoo cows with the offspring meat quality grades of 1++ and 1+ were 18.6 and 21.2%, respectively. The rates of blastocyst development were 26.3, 20.7, 20.7, 17.2 and 31.2% from Hanwoo cows with the meat quality grades of 1++, 1+, 1, 2 and 3, respectively. Fiftyseven transferable embryos were recovered from 11 Hanwoo donor cows (5.2/head) with the high offspring meat quality grades of 1++ and 1+ in vivo, and the pregnancy rate after embryo transfer was 61.1%. In conclusion, these results suggest that in vitro embryo production from the ovaries of cows with the high meat quality grades using individual culture system can be used an efficient method for livestock improvement. In addition, for the successful industrialization of embryo transfer, conception rate should be improved.

The objective of this study was to investigate meat quality and nutritional composition of 10 cuts (loin, striploin, chuck roll, chuck tender, short plate, brisket, bottom round, top sirloin, eye of round, and top round) from quality grade 1 beef from 11 Hanwoo steers at Hanwoo Experimental Station of National Institute of Animal Science. The protein contents were higher in top round (Udoon) and eye of round (Hongduke) and lower in loin (Dngsim) and short plate (Abjin) when compared to the other cuts (p<0.05). Whereas the intramuscular fat contents were highest in loin (12.51%), those were lowest in top round (4.14%) (p<0.05). The calories were higher in loin and short plate and lower in top round, chuck tender (Guri), top sirloin (Bosup), eye of round, chuck roll (Moksim), and bottom round (Sulgit) (p<0.05). The cooking loss (%) was 24.38% in loin and it was lower than the other cuts (p<0.05). The bottom round had higher water holding capacity (WHC) and chuck tender had lower WHC than those in the other cuts (p<0.05). In meat color, L* values were higher in loin and lower in top round than the other cuts (p<0.05). Total saturated fatty acid contents were higher in loin and lower in bottom round than the other cuts (p<0.05). In amino acid compositions, top round had significantly higher than those in the other cuts (p<0.05). The iron contents were higher in chuck tender and chuck roll contained higher iron contents than those of the other cuts (p<0.05). In conclusion, the meat quality and nutritional properties were significantly different among 10 cuts in the same quality grade of Hanwoo beef. Therefore, the provision of the meat quality and nutritional information of 10 cuts to consumers could be important for utilization and balanced consumption of different cuts.

Analysis of meat quality grade based on the DNA identity test samples were done on 320 Hanwoo (Korean cattle) raised in Gyeonggi region of Korea. 62.29% of cows and 91.35% of steers showed high quality which was above 1st beef grade. However, differences were observed between Gyeonggi Hanwoo and total slaughtered Hanwoo in Gyeonggi in the year 2009, though the sampling was entirely based high quality meat. Meat samples of pedigree registered cattle showed high rate of above 1st meat grade compared to advanced and fundamentally registered cattle. Pedigree registry is associated with quality grade of beef like the sex of cattle. Appearance rate of above 1st beef grade in offsprings of the top 9 Korean Proven Bulls produced through mating to Gyeonggi Hanwoo was 43.27% which was found to be higher than the average grade in cows (47.3%) and was 13.08% higher than the average grade in steers (77.49%). Our results showed superior genetic characters of Korean Proven Bulls which favors and influence the meat quality grade of their offsprings. Furthermore, our results claim that sex of Hanwoo irrespective of pedigreed or Korean Proven Bulls affects and/or influence the meat quality. Conclusively, the results could therefore be used as a basic data for the improvement of beef quality. However, paternity test by DNA typing and huge sample needs to be analysed to authenticate the findings.

In this study, the analysis of meat quality grade was carried out on the DNA identity test samples of 452 Hanwoo (Korean cattle) raised in Gyeongnam region in the year 2009. Appearance rate of above 1st grade from cow (70%) and steer (93.16%) showed high quality grade. On the other hand, there were the difference between this study and slaughtered Hanwoo in Gyeongnam in the year 2009 - appearance rate of above 1st grade from cow (58.77%) and steer (82.99%). It expect considered influence of the samples for beef DNA identity test that collected mainly high quality meat. Quality grade by registry classification about collected samples showed correlation between pedigree classification and quality grade that appearance rate of above 1st grade highly observed pedigree registry more than advanced registry, advanced registry than fundamental registry. Although limited to DNA identity test samples, KPN (Korean Proven Bull's Number) 452 and KPN 407 was preferred for breeding in Gyeongnam. Also average appearance rate of above 1st grade in offsprings of the top 10 Korean Proven Bulls used mating is 95.35%. It means that Korean Proven Bulls influence meat quality of offsprings positively. Thus, this analysis is expected to be a base data for the improvement of meat quality of Hanwoo raised in Gyeongnam region.

We separately cultured follicular oocytes collected from individual ovaries of slaughtered Korean native cows and examined both the embryonic development rate and pregnancy rate after embryo transplantation according to the meat yield and quality grades of the source beef carcass. Oocytes from meat yield grade B cows exhibited a higher fertilization rate and embryonic developmental rate to the eight-cell stage than oocytes from grade A or C animals (p<0.05), but there was no significant difference in rate of development to the blastocyst stage among meat yield grades A, Band C. The oocyte cleavage rate and development rate to the eight-cell stage from meat quality grade 3 cattle was higher than grades 1++, 1+, 1 and 2 (p<0.05). Embryos derived from grade animals displayed a development rate to the blastocyst stage of 19.4%, which was also higher than all other meat quality grades (p<0.05). Transplantation of in vitro-cultured oocytes from meat yield grade A ovaries led to a higher pregnancy rate (64.2%) than in vitro-cultured oocytes from meat yield grade B ovaries (56.5%), but there was no significant difference between the two groups in pregnancy or abortion rates. In conclusion, embryonic development rate and pregnancy rate has a close relation to meat quality grades of the source beef carcass, this results is to give information for the Korean native cows improvement of breed.