The KLF(Kruppel-like factors) are transcriptional regulators that including the C2H2 zinc-finger motif and regulation of cell growth, cell differentiation, and development. In this study, mRNA and total DNA was extracted from the meat around the backbone of 130 cattle that has economic traits score. The KLF11 gene was act on the center of the main pathway in associated with the development and growth of cells and the fat metabolism. Genetic polymorphism was detected by DNA sequencing. A total of four SNPs(G9047A, C9104G, G9131A, C9170T) were identified in exon 4 regions, statistical association analysis revealed that the G9131A polymorphism were significantly associated with marbling score. The real time quantitative PCR to investigated gene and miRNA expression patterns and identify the relation of economic trait in Korean Native Beef Cattle. Gene expression level linked to KLF11 genes was investigated by determining its association and variation with the economic traits in Korean Native Beef Cattle. The increment of KLF11 gene expresstion level is resulted in increasing marbling score(MS). We found that expression profile of KLF gene and mir-494 was contrast tendency because the lower expression ratio of gene was the higher marbling score rating was when we analyzed expression profile ofKLF gene and mir-494. Therefore, this result has useful in improvement of livestock in Korean cattle.

In this study, the texture, nucleotide-related compounds, and sensory characteristics of dry-aged beef, made from third quality grade Hanwoo beef (Korean native cattle), were investigated according to aging periods. Loin cuts obtained from three different Hanwoos were dry-aged under the specific conditions (controlled temperatures, humidity, and air flow) during 0-7 weeks. With increasing aging periods, textures were significantly decreased after 5 weeks (hardness: from 13,264±2,033 to 7,112±1,743 g; chewiness: from 4,107±1,467 to 2,334±780) and four sensory characteristics were significantly increased after 3 weeks (texture: from 2.2±1.0 to 6.2±1.1; flavor: from 3.9±0.7 to 6.2±1.5; whole preference: from 2.5±0.8 to 6.3±1.3; purchase intention: from 3.7±1.4 to 6.0±1.5) except for color (p<0.05). On the other hand, the concentrations of IMP which is related to the umami flavor of beef were significantly decreased with increasing aging periods (from 40.44±5.97 at 0-week to 7.44±2.43 μg/ mg at 7-week) (p<0.05). These results obtained in this study could provide an useful data base for the quality control of dry-aging.

This research was conducted to estimate the effect of packaging methods on the color and taste-related precursors in Hanwoo (Korean cattle) beef during aging. Following packaging with vacuum (VACP), low oxygen-modified atmosphere (LOMAP; 0% O2/20% CO2/80% N2) or vacuum skin+LOMAP (VSP+LOMAP), the loins and top rounds were aged at 2℃ for 14 days and lipid oxidation (TBARS content), surface color, glucose and lactate contents were measured. TBARS and glucose contents were not different by packaging methods in both loins and top rounds. The a* (redness), b* (yellowness) and C* (chroma) values were higher (p<0.05) in VACP-aged beef as compared to the other beef. Lactate content was significantly higher (p<0.05) in both LOMAP- and VSP+LOMAP-aged beef than in VACP-aged beef at day 14 of aging. These findings suggested that VACP was the most effective in maintaining color stability but LOMAP was more effective in maintenance of some taste-related precursor compared to VACP.

The objective of this research was to evaluate the changes of water-soluble flavor precursors in loin and top round from Hanwoo (Korean cattle) beef during aging at 2℃ for 14 days. The glycogen, glucose and lactate contents were not significantly influenced by beef parts and aging. Among nucleotide-related compounds, inosine 5'-phosphate (IMP) and inosine contents were significantly (p<0.05) lower in loin compared with top round but hypoxanthine content was not significantly different between beef parts. Moreover, during aging, IMP content significantly (p<0.05) decreased while inosine and hypoxanthine contents significantly (p<0.05) increased. It is concluded that aging highly affected the nucleotide-related compounds among water-soluble flavor precursors in loin and top round from Hanwoo.

Jeongseon-gun had 892 Korean beef cattle farmers, and had 9,180 Korean beef cattle in September, 2010. Average fed cattle by farm was less than 20 heads. The small scale breeding ratio was higher than the case of Gangwon-do and the average country level. Jeongseon-gun tries to increase the beef cattle to 20,000 in oder to increase farm income. The purpose of the study is to analysis the farmer's intention to the increasing feed scale. Data were collected by questionnaire. Frequency analysis, factor analysis and cluster analysis were used to analyze. In the results of frequency analysis, about 92% respondents were agreed to expand the increasing scale to 20,000 heads. In order to accomplish the goal, about 63% respondents wanted complex for Korean native cattle breeding. About 62% respondents had intention to increase the feeding cattle heads. In the results of factor analysis, four factors were derived as "Government support", "Infrastructure construction", "Brand development" and "Construction logistics system". In the results of cluster analysis, three clusters were derived as "group that does not need support from the government", "group that needs construction of logistics system" and "group that needs support system".

This study was conducted to investigate the effect of age on the oxidative stability of Hanwoo (Korean cattle) cow beef. The samples of M. longissimus dorsi from 65 and 133 months-old-Hanwoo cows (4 and 3 heads, respectively) were stored at 4±0.2℃ for 9 days. The proximate composition, total myoglobin content, pH value, water-holding capacity and drip loss were not significantly affected by age. At day 9 of storage, the lipid oxidation (2-thiobarbituric acid reactive substances) was significantly (p<0.05) higher in beef from 133 months-old-cows than 65 months-old-cows. Lower (p<0.05) oxymyoglobin concentration and R630-R580 value and higher (p<0.05) metmyoglobin concentration were observed in beef from 133 months-old-cows at day 9 of storage than 65 months-old-cows. The CIE a*, b* and C* values were significantly (p<0.05) lowered in beef from 133 months-old-cows at day 9 of storage than 65 months-old-cows. It could be concluded that old age decreased the lipid oxidation stability and myoglobin oxidation stability in Hanwoo cow beef.

This study was carried out to investigate the effect of muscle part and aging period on free amino acids and aroma compounds of Hanwoo (Korean cattle) cow beef. The M. longissimus (ML) and M. semitendinosus (MS) from 101 mon-old-cows were aged at 2℃ for 14 d. The free amino acids concentration increased in both ML and MS on 14 d of aging. In ML, asparagine, glutamine, histidine, glycine, threonine, arginine, tyrosine, phenylalanine, isoleucine, leucine and lysine were significantly (p<0.05) higher than those in MS. Varieties of aldehydes, ketones, alcohols, hydrocarbons, nitrogen and sulfur compounds were detected in both ML and MS and majority of these compounds showed increasing trend on aging. The ML had higher 14 aldehydes (acetaldehyde, 2-methylpropanal, 3-methylbutanal, 2- methylbutanal, pentanal, hexanal, heptanal, E-2-heptanal, octanal, 2-octenal, 2-nonenal, E-2-decenal, E,E-2,4-decadienal and 2-undecenal), 5 ketones (2-propanone, 2,3-butanedione, 2-butanone, 2-heptanone and 2,3-octanedione), 4 alcohols (ethanol, 1-pentanol, 1-hexanol and 1-octanol), 3 hydrocarbons (3-ethyl-2-methyl-1,3-hexadiene, 3- methyldecane and 2,2-dimethyloctane) significantly (p<0.05) compared with MS. However, the MS had higher 5 nitrogen and sulfur compounds (methanethiol, dimethyldisulfide, fufural, 2,5-dimethylpyrazine and 2-octylfuran) significantly (p<0.05) compared with ML.

This study was carried out to investigate the effect of amino acids complex and choline supplementation on the antioxidant enzyme activities and oxidative stability of Hanwoo (Korean cattle) beef. Fifteen months-old-Hanwoo steers were assigned into two groups and fed on a basal diets with or without amino acids complex (≥25% L-lysine monohydrochloride+≥8% DL- methionine)+choline (≥25% choline chloride) for 12 months. After slaughter, the M. longissimus from carcasses were stored at 4℃ for 7 days. Catalase, glutathione peroxidase and total superoxide dismutase activities were found to be unaffected by supplementation of amino acids+choline. After 2 days of storage, significant decline (p<0.05) in lipid oxidation (2-thiobarbituric acid reactive substances, TBARS) was observed when supplemented with amino acids+choline. However, supplementation of amino acids+choline maintained meat color as indicated by higher CIE L* (Lightness), a* (Redness), b* (Yellowness) and C* (Chroma) values during storage. It was therefore concluded that supplemental amino acids+choline could stabilize the lipid oxidation stability and meat color in Hanwoo beef.

The current study was carried out to investigate the effect of addition of Rhus veniciflua Stokes oil (RVSO) and black garlic extract (BGE) on the lipid oxidation in Hanwoo (Korean cattle) beef model systems. The RVSO at 0.2% inhibited the TBARS (2-thiobarbituric acid reactive substances) formation when tested in liposome model system. The antioxidant effect of RVSO was further found to be similar to 0.2% butylated hydroxy toluene (BHT) and 0.01% vitamin E. On the other hand, BGE at 0.1% also showed the inhibition of TBARS formation in 4% NaCl-added Hanwoo beef patty and found to have slightly lower (p<0.05) effect than 0.1% vitamin E but higher (p<0.05) effect than 0.1% BHT. Results of this study indicated that both RVSO and BGE possess strong antioxidant effects and help to increase the oxidative stability in Hanwoo beef products.

This study was carried out to propagate Korean native cattle using beef recipients by embryo transfer. Seven Korean native cattle donors were superovulated with FSH 32mg and Embryos collected from donors were frozen and preserved in National Animal Breeding Institute. Frozen-thawed embryos were transferred to synchronized 40 beef recipients nonsurgically in Daekwanryeong Branch of National Animal Breeding Institute. The results obtained were as follows : 1. Total ova and transferable embryos per donor were 11.4 and 11.1 from 7 donors, respectively. 2. Among 40 recipients transferred with frozen-thawed embryos, 20 were pregnant(50.0%). 3. The pregnancy rate according to time from embryo thawing to transfer was higher when transferred within 3 hours than after 3 hours(57.6% vs. 14.3%). 4. The cow recipients showed slightly higher pregnancy rate than the heifer(53.3% vs. 48.0%). 5. Two grade embryos showed higher pregnancy rate than 1 grade(66.7% vs. 45.2%).

The Coronavirus disease (COVID-19), first identified in China in December 2019, has widely spread worldwide and is an ongoing pandemic. It is expected that the ripple effect of COVID-19 on the global economy including the agricultural sector will increase substantially if not properly controlled shortly. This study examines the potential impact of COVID-19 on the Korean beef cattle sector and farm labor demand for Korean beef cattle using a dynamic partial equilibrium model. The agricultural production value and farm labor demand for Korean beef cattle in the scenario assuming pessimistic GDP growth rate (-1.2% in 2020) with no direct supply shocks fell by up to 4.00% and 0.67%, respectively, compared to the baseline which represents the future without COVID-19 outbreak. On the other hand, the agricultural production value and farm labor demand for Korean beef cattle in the scenario assuming both pessimistic GDP growth rate and supply shocks (-12.7% beef imports and + 2.4% feed cost in 2020) increased by up to 12.08% and 1.99%, respectively, compared to the baseline.

Korea-US FTA amendment became effective January 1, 2019 through several trade negotiations between the two countries. These amendments did not include changes in the agricultural sector. However, given the policy direction of the Trump administration, it is difficult to be certain that the existing Korea-US FTA on the agricultural sector will remain unchanged. This study examines the potential impact of changes in the US beef import tariff rates under the Korea-US FTA, which is progressively eliminated until 2026 using a dynamic partial equilibrium model. The modelling system is simulated with 100% decreases of tariff rates over 2020~2026 period and then compared to the baseline which is developed based on the current Korea–US FTA tariff rates. According to the scenario analyses results, 100% decreases of US beef tariff rate lowered Korean beef cattle production value up to 4.23%. Looking at this change in terms of absolute value rather than percentage, the total production value over 2020~2026 is expected to decrease by 815 billion won compared to Baseline. This reduction in production value in dynamic analysis is 67 billion won higher than the comparative static analysis.