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.

The aim of this study was to identify allele variability and frequencies of six microsatellite markers (BM861, INRA124, INRA189, UMN0103, UMN0307 and UMN0504) specific to the Y-chromosome. DNA samples from 147 males of three Korean native and seven exotic cattle breeds were tested. Three (Chikso, Heugu, and Jeju black cattle) Korean native cattle (KNC) breeds showed Bos taurus genotype. In the neighbor-joining tree, based on Nei’s DA genetic distance, ten breeds represented main group. In addition, Bayesian clustering result showed that 3 main clusters are for individual allele variability and frequencies. Moreover, KNC breeds showed differences in genotype with B. taurus type when compared to previous studies. The molecular information of paternal lineage in this study would be useful for the conservation and utilization of three KNC breeds as genetic resources.

Bovine coat color is decided by the melanocortin receptor 1 (MC1R) genotype mutation and melanogenesis. Specially, in the various cattle breeds, dominant black coat color is expressed by dominant genotype of ED, red or brown is expressed in the frame shift mutation of recessive homozygous e by base pair deletion and wild type of E+ is expressed in various coat colors. However, not very well known about the effected of MC1R genotype mutation on the coat color through family lines in KBC. Therefore, this study were to investigate effect of MC1R genotype mutation on the coat color, and to suggest mating breed system in accordance with of MC1R genotype for increased on brindle coat color appearance. Parents (sire 2 heads and dam 3 heads) and offspring (total : 54 heads) from crossbreeding in KBC family line with the MC1R genotype and phenotype records were selected as experimental animals. The relationship between melanocortin 1 receptor (MC1R) genotypes expression verified by PCR-RFLP, and brindle coat color appearance to the family line of the cross mating breed from MC1R genotype pattern was determined. As a result, 4MC1R genetic variations, E+/E+ (sire 1), E+/e (sire 2 and dam 3), E+/e with 4 bands of 174, 207 and 328 bp (dam 1) and E+/e with 3 bands of 174, 207, 328 and 535 bp (dam 2) from parents (sire and dam) of KBC. However, 3 genetic variations, e/e (24%), E+/E+ (22%) and E+/e (56%) were identified in offspring. Also, brindle coat color expressrated was the e/e with the 0%, E+/E+ with 67% and E+/e with 77% from MC1R genotype in offspring on the cross mating of KBC. Furthermore, when the sire had E+/e genotype and the dam had E+/E+ with the 3 bands or E+/e genotype, and both had whole body-brindle coat color, 62% of the offspring had whole body-brindle coat color. Therefore, the seresults, the mating system from MC1R genotype patterns of the sires (E+/e) and dams (E+/E+ with the 3 bands or E+/e) with brindle coat color may have the highest whole body-brindle coat color expression in their offspring.

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".

The role of Fatty acid binding protein 4 (FABP4) gene is critical for lipid metabolism and for maintaining homeostasis in adipocytes. Association between Hanwoo carcass traits and FABP4 gene g.7516G>C SNP has been reported previously, however, its association and how does it influence Korean brindle and black cattle has not been demonstrated and established till date. For this purpose, the study was planned to analyze the SNP association (Single Nucleotide Polymorphism) (g.7516G>C) in FABP4 gene and gather genetic information on economic traits of Korean brindle cattle and black cattle. As per sequence of bovine FABP4 gene available (Genbank accession No. NC_007312.4), one pair of primers (5’-ATA TAG TCC ATA GGG TGG CAA AGA-3’ and 5’-AAC CTC TCT TTG AAT TCT CCA TTC T-3’) was designed to amplify a 452bp product of the FABP4 gene including the region of 7417–7868. The SNP, detected by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) methods using restriction enzyme MspA1I, was genotyped in 117 animals of brindle cattle and 24 animals of black cattle population. Statistical analysis revealed that the FABP4 genotype significantly (p<0.05) affect with carcass weight, but there was no significant association with any other economic traits was observed in brindle as well as in black cattle. In conclusion, these results suggested that SNP (g.7516G>C), located in FABP4 gene, could be used as important DNA marker of economic traits in Korean brindle cattle. Furthermore, we suggest that additional samples needs to further analysed to make related data exclusively authentic.

The melanocortin receptor type 4 (MC4R) gene is expressed in the hypothalamus and regulates energy intake and body weight. Recently, it has been reported that obesity and energy balance in human were also regulated by the MC4R gene. Therefore the objective of this study was to identify the polymorphism on the MC4R gene SNP C1786T and its association with economic traits in Korean native cattle (brindle and black cattle) by PCR-RFLP. A total of 125 cattle from the two breeds were tested for economic traits (meat quality index, backfat, thickness, carcass weight, longissimus muscle area and marbling score) and data was analyzed using SAS program. In the results, C allele had highest frequency than G allele frequency in the both breeds and the gene was significantly associated with meat quantity index and backfat thickness in brindle cattle breed. However, in black cattle, the gene was significantly associated with longissimus muscle area (p<0.05). These results suggest that C1786T SNP of the MC4R gene may be useful as a genetic marker for economic traits in the brindle and black cattle.

The objective of this study was to evaluate several types of uterine bacteria in Hanwoo. uterine bacteria from randomly selected 5 uterus was collected by flushing methods into a sterilized 1.5 ml centrifuge tube and was inoculated onto MacConkey agar and blood agar, respectively. After being incubated for 5% CO2, aerobic or anaerobic condition at 37℃ during 48h, bacterial colonies were selected and re-inoculated onto blood agar plates. Re-cultured colonies were identified by Gram staining and finally identified using Vitek system. The identified bacteria were Staphylococcus lentus, Staphylococcus sciuri, Staphylococcus vitulinus, Staphylococcus warneri of Gram (+) and Rhizobium radiobacter, Sphingomonas paucimobilis of Gram () bacteria. Although, pathogenicity of identified bacteria was unclear, the bacteria can have an effect on the uterine microenvironment. Therefore, repetitive research will be required to determine the effects of bacteria in cattle exposed to a various environment.

Solution of glycerol, ethylene glycol, sucrose, dextrose (GESD) and cryotop methods were carried out to investigate the survivability on vitrification of embryos. Embryos cultured in vitro were vitrified by GESD of 10 or 8 step and cryotop methods of 6 step, from cryopreservation step to frozen-thawed and culture step. Survival rate and ICM, TE cells of embryos were investigated after frozen-thawed 24 h. As a results, cryotop method was significantly (p<0.05) higher ( vs. , ) than GESD 10 or 8 step methods on survivability. Also, In ICM cell number, cryotop method was significantly (p<0.05) higher to cells than GESD 8 step method. TE cell number was significantly (p<0.05) highest to cells in cryotop method. On the other hand, survival rate, TE and total cell number were all the significantly (p<0.05) high, except ICM in GESD 10 step method between GESD 10 step method and GESD 8 step method. In conclusion cryotop method was to be most effective, but it is considered necessary to study vitrification method for step-by-step freezing and thawing process.

This study was carried out to effects of ethylene glycol concentration, sucrose and culture day of in vitro production embryo on slow-down freezing in Hanwoo. 6, 7, 8 and 9 day embryos produced in vitro were frozen using 1.8M EG+0.1M sucrose, 1.8M EG+0.5% BSA and 1.5M EG+0.1M sucrose media. Survivability was confirmed after frozen-thawed 24 and 48h and ICM, TE cell number were counted by Hoechst 33342 and PI staining after frozen-thawed 24h. As a result, 1.8M EG+0.1M sucrose group was most significantly (p<0.05) higher compared with the other treatment groups on survivability, TE and total cell number after frozen-thawed 24h (, and ). ICM number did not found significant (p<0.05) differences between the three treatment groups. in 6, 7, 8 and 9 day of embryos using three types of freezing media, frozen-thawed, 1.8M EG+0.1M sucrose groups with embryos cultured 8 day was significantly (p<0.05) highest survivability to after frozen-thawed 24h. 1.5M EG+0.1 sucrose group with embryos cultured 9 day was significantly higher survivability than group of embryos cultured 8 day after frozen-thawed 24 and 48h. In conclusion, 1.8M EG+0.1M sucrose media is considered to be effective to cryopreservation of embryos cultured 8 and 9 day.

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.

After spermatogenesis, spermatozoa come in contact with fluids in the epididymis where they mature. During ejaculation, spermatozoa are mixed with secretions from prostate gland, vesicular glands, and bulbourethral glands. During natural mating, seminal plasma is deposited in the female reproductive tract eliciting various physiological and immunological responses. With the advances in proteomics, the components of seminal plasma have been identified and the information may be valuable in identifying markers for fertility. Components of seminal plasma that affect fertility have been discovered and the mechanism of action of these factors has been determined. The objective of this study was to determine the specific seminal plasma proteins from Korean native cattle, Hanwoo, and Korean native brindle cattle (KNBC) with the long term goal of improving fertilization rate. After SDS-PAGE and 2-dimensional gel electrophoresis, proteins were identified by Q -ToF analysis. They include plasma serine protease inhibitor precursor and platelet-activating factor acetylhydrolase after SDS-PAGE. Number and density of the spots in 2-dimensional gels were higher in KNBC than Hanwoo. Proteins identified from the paired spots of both breeds include chain A, bull seminal plasma PDC-109 Fibronectin Type II module, BSP-30 kDa precursor, and Spermadhesin Z13 or its precursor. Interestingly, some proteins were identified from multiple spots. The functional differences of these diverse forms of the proteins may require further studies. With their previously reported roles in sperm capacitation by these proteins, the studies on the mechanism of action, ligand interaction and the variation in the genome may help improving fertility in cattle.

The objective of this research was to investigate the effect of dietary cottonseed meal (CSM) supplementation on carcass and meat quality characteristics of Hanwoo (Korean cattle) bulls. Twenty two months-old-Hanwoo bulls of eight heads (4 heads per treatments) were fed for 5 months on a diet with or without (control) CSM (500 g/head/day). The samples of M. longissimus dorsi from carcasses were used for the quality measurement. Dietary CSM supplementation did not affect the carcass traits of bulls and pH value, drip loss, water-holding capacity and fatty acid composition of beef loin. Crude protein and crude ash content of beef loin were significantly (p<0.05) higher in beef loin from bulls fed CSM than in the control. During storage of 5 days at 4℃, CIE a*, b*, C* and total color values were significantly (p<0.05) higher in beef loin from bulls fed CSM than in the control. Overall, the present results indicate that dietary CSM supplementation may improve the oxidation stability of Hanwoo beef loin.

This study was conducted to estimate heritabilities and genetic and phenotypic correlations among growth traits (weaning weight, weight of 12 month, weight of 18 month, weight of 24 month). Growth data collected from steers (n=3,321) and 8,818 animals in pedigree were used for estimation of genetic parameters. Traits evaluated included live weight at 4 month (W4), 12 month (W12), 18 month (W18) and 24 month (W24). Parameters were estimated using an multitrait animal model and derivative-free restricted maximum likelihood procedures. Heritabilities estimated for growth traits at W4, W12, W18 and W24 were 0.21, 0.11, 0.08 and 0.14, respectively. Genetic correlations were in the range of 0.79 to 0.87. Phenotypic correlations were in the range of 0.16 to 0.81.

This study evaluated a method of sorting X and Y chromosomes based on size using the forward angle light scatter related refractive index (FSC) of a flow cytometer. Hanwoo bulls sperm were separated to X and Y chromosomes by the parameters of FSC or Hoechst 33342 intensity. As a result, using monitor program linked flow cytometry during sorting processing, the purities were or for the X-fraction and or for the Y-fraction in the two sperm sorting methods. There were no differences in the X and Y ratios (X and Y %) between the sperm sorting methods based on FSC or DNA content. The proportions of female and male embryos used for in vitro fertilization and development were or , and or when sperm were processed using the sex sorting method by FSC or Hoechst 33342. In conclusion, further study is needed to determine the optimum procedure and improve the nozzle to enhancing sorting accuracy or efficiency. Also, the findings of this study do not negate the possibility that the difference method of sperm sorting cannot use a UV laser beam.

This study evaluated a sexed sperm ability to produce embryos by flow cytometer. Hanwoo bulls sperm were separated to X and Y sperm via Hoechst 33342 stained with near UV laser or performed the pre-sorted without near UV laser beam in flow cytometry. Pre-sorted sperm had significantly higher viability (84±1.15 %, p<0.05) compared to other sorted groups in frozen-thawed semen. For fresh semen, pre-sorted sperm had the higher viability (79±3 %, p<0.05) than those of the X and Y sperm (44.7±1.67 and 41.7±1.2 %) separated by differences of DNA content. On the other hand, pre-sorted and X sperm sorted according to differences in DNA content had significantly higher viabilities (24.3±1.2 and 25.7±0.9 %, p<0.05) compared to that of the sorted Y sperm (13.7±1.2 %) in the hypoosmotic swelling test. The proportion acrosome reaction in the sorted X sperm was higher (55.0±1.7 and 45.0±1.5 %) than those of the sorted Y-sperm (32.3±0.9 %, p<0.05). However, the sperm morphologies of the sorted groups were not significantly differences. In conclusion, the sex-sorting procedure by flow cytometry affected some characteristics of Hanwoo sperm. Further study is needed to determine the optimal procedures to enhance male and female embryos and sorting accuracy.

Economic traits are quantitative traits and are mostly controlled by a large number of genes. Some these genes tend to have a large effect on quantitative traits in cattle and are known as major genes primarily located at quantitative traits loci (QTL). However, in practice, QTL is linked to allele associates of the gene controlling traits of interest. It is hypothesized that if QTL explaining a part of genetic differences between animals are detected, the effect of the genes located at QTL could assist in estimating an animal’s true genetic value. Therefore, QTL information could probably provides accuracy of breeding value estimation as well as more genetic gain through selection of animals at relatively younger age. Marker assisted selection (MAS) is the indirect selection process where a quantitative trait of economic importance is selected not just based on the trait itself but also on the basis of marker linked to QTL. MAS could be useful for traits that are difficult to measure, exhibit low heritability, and are expressed late in development. Major genes which are responsible for QTL could possibly be identified first by using different techniques such as gene expression analysis and QTL mapping. Thereafter, the information generated could be implemented for MAS in estimating breeding value. In this review we focused on delivering genome information into Hanwoo breeding program.

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.

The Oct-4 (octamer-4), a member of the POU family transcription factor, is expressed in early mouse embryogenesis and in pluripotent embryonic stem (ES) lines. Oct-4 expression is thought to remain confined to the germline after gastrulation in the embryo. Therefore, the study was designed to, study the location of Oct-4 protein in the ovaries, placenta and testis of Korean native cattle (Hanwoo). Expression of Oct-4 mRNA in the ovaries and placenta of bovine was confirmed by RT-PCR and immunohistochemical analysis. Oct-4 was expressed in granulosa, thecal cells irrespective of the shape and size of follicles and endometerium of Korean native cattle (Hanwoo). Expression of Oct-4 was profound in all the tissues of Korean native cattle (Hanwoo) suggestung their role in them. Oct-4 localization and expression could contribute to further developmental studies in Korean native cattle (Hanwoo).