• Korean Journal of Agricultural Science
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• v.43 no.5
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• pp.810-817
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• 2016

The aim of this experiment was to determine the effect of a high-energy diet on the level of serum metabolites and on carcass characteristics of Hanwoo steers. High energy diets have been used for enhancing intramuscular adipose tissue in high quality beef cattle. However, there is not much information about the physiological reactions to this diet. We hypothesized that a high energy diet would increase blood metabolites and the meat quality of Hanwoo steers during the early and final fattening periods. A $2{\times}2$ factorial arrangement (High, Control, and Early, Final) in a completely randomized design was used to feed 24 Hanwoo steers. Two steers were kept in the same pen and 12 pens were used for the experiment. Blood was drawn from each steer on the first week of every other month from 11 to 28 months. Overall Average Daily Gain (ADG) and feed efficiency were not different between high energy and control diets (p > 0.05). However, Dry Matter Intake (DMI greater with the control diet than DMI with the high energy diet during the final fattening period (p < 0.05). Serum non-esterified fatty acid (NEFA) concentrations were greater in the control diet group than in the high energy diet group during the final fattening period (p < 0.05). However, serum albumin, glucose, total protein, triglyceride, and phosphorus were greater in the high energy group than those of the control group (p < 0.05). Carcass traits or physico-chemical characteristics were not different between high energy diet treatment and the control. These data indicated that a high energy diet (+ 3% TDN) increased serum triglyceride during early fattening periods and decreased non-esterified fatty acids during final fattening periods in Hanwoo steers.

• Food Science of Animal Resources
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• v.22 no.3
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• pp.228-233
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• 2002

To investigate the effects of submersion aging in chilled water on tenderness and microbial growth of vacuum-packed beef, the semimembranosus muscles of Hanwoo (Korean cattle) was sampled at a commercial meat plant at 24 hrs postmortem. The samples were cut to 2.5 cm thick steaks and randomly assigned to following two treatments. The samples were stored in conventional refrigerator at 4$^{\circ}C$ after vacuum packaging for control whereas the other vacuum-packed samples were submersed in chilled water at 1$^{\circ}C$ for treatment, and both samples were stored for 14 days to measure total plate counts (TPC), sarcomere length, free calcium concentration, shear farce value and myofibrillar fragmentation index (MFI). The sarcomere length of treatment was significantly (p<0.05) longer than that of control at 3 days aging. Result suggested that submersion in chilled water of vacuum-packed beef might be effective to improve tenderness of meat compared to storage in conventional refrigerator. There were no significant differences in the shear force and MFI between control and treatment during storage. However, the free calcium concentration of samples from treatment was significantly (p<0.05) higher than that of control at 7 days of ageing. This result indicated that the lower shear force value and the longer sarcomere length of samples from treatment might be due to increasing the free calcium ion concentration in sarcoplasm during storage. On the other hands, samples from control showed significantly (p<0.05) higher number of microbial (TPC) compared to treatment during storage. from results obtained, submersion in chilled water of vacuum-packed beef could be recommended as a desirable aging method to improve tenderness of Hanwoo compared to aging in conventional refrigerator.

• Food Science of Animal Resources
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• v.24 no.3
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• pp.253-259
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• 2004

The effect of dietary clay mineral on meat quality in M. longissimus of Hanwoo (Korean cattle) bull beef during refrigerated storage (4$^{\circ}C$) was investigated. Experimental groups were divided into control (basal diet) and CT-1.25% (basal diet + 1.25% clay mineral) groups. There was no significant differences in proximate and fatty acid compositions between control and CT-1.25% groups. The pH of control group was significantly (p<0.05) changed during storage, but CT-1.25% group was little affected by storage time. CIE a＊ (redness), chroma (C＊) values and R630-R580 were significantly (p<0.05) decreased during storage for both groups. In particular, those values decreased more rapidly in the control group. The rate of metmyoglobin accumulation during storage increased more rapidly in the control group. Therefore, discoloration in the control group was more accelerated compared to the CT-1.25% group. TBARS (thiobarbituric acid reactive substances) which represents lipid rancidity were significantly (p<0.05) lower in CT-l.25% group than in the control. Water-holding capacity (WHC) was significantly (p<0.05) increased during storage for both groups, and CT-1.25% group had significantly (p<0.05) higher WHC than control group. Consequently, feeding of clay mineral (1.25%) was effective in increasing meat color stability and WHC, and retarding lipid oxidation than did control group.

• Korean Journal of Agricultural Science
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• v.43 no.4
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• pp.603-611
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• 2016

The aim of this study was to analyze the contribution factors (backfat thickness, eye muscle area, carcass weight, marbling score, and feeding period) affecting meat unit price (South-Korean Won / Kg of meat). The best slaughtering age to maximize unit price was also assumed. All data used in this study were acquired from the Korea Institute for Animal Products Quality Evaluation from 2010 to 2014. Contributions to the estimated unit price of cows by the following factors, backfat thickness, eye muscle area, carcass weights, feeding period, and marbling score were 2.65%, 0.04%, 1.58%, 1.58%, and 95.72%, respectively. Contribution to estimated unit price of steers by the same factors (backfat thickness, eye muscle area, carcass weights, feeding period, and marbling score) were 7.88%, 1.24%, 0.07%, 90.81%, and 95.72%, respectively. Slaughtering ages ranged from 26 to 36 months and the data were separated into each month for an 11 month period. The unit price of meat from Hanwoo slaughtered at 30 months was highest among groups. The lowest unit price was observed in the group belonging to the Hanwoo slaughtered at 36 months. In conclusion, of all contributing factors, marbling score affected unit price the most. Based on our results, it is recommended that the optimal slaughtering age be set at 30 months to maximize unit price. Moreover, the feeding of beef cattle past 30 months of age is not recommended because of the increase in feeding costs.

• Food Science of Animal Resources
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• v.25 no.2
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• pp.196-202
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• 2005

This study was carried out to investigate the effect of dietary Rhus verniciflua Stokes on the quality of Hanwoo (Korean cattle) beef during cold storage $(4^{\circ}C)$ after thawing. After 4 groups (3 heads/group) of 22 months-Hanwoo (Korean cattle) steen were fed a common basal diet with 0, 2, 4 and $6\%$ Rhus verniciflua Stokes (RVS) powder for 4 months prior to slaughter, samples of M semimembranous from 12 carcasses were stored at $-20^{\circ}C$ for 9 months. Crude fat was significantly lower in 4 and $6\%$ RVS treatments than in control (p<0.05). pH value was significantly higher in4 and $6\%$ RVS treatments than in control from 2 and 5 days (p<0.05). Thawing loss was not significantly different among the treatments but drip loss was significantly lower in 4 and $6\%$ RVS treatments than in control during storage (p<0.05). CIE $L^{\ast}$ value was significantly lower in RVS treatments than in control during storage (p<0.05) and CIE $a^{\ast}$ value was significantly higher in 4 and $6\%$ RVS treatments than in control (p<0..05). CIE $b^{\ast}$ value was significantly higher in control than in $6\%$ RVS treatment in 0 days (p<0.05) but it was significantly higher in $4\%$ RVS treatment than in control in 7 days (p<0.05). CIE $C^{\ast}$ value was significantly higher in $4\%$ RVS treatment than in control during storage (p<0.05) and CIE $h^0$ value was significantly lower in $4\%$ RVS treatment than in control (p<0.05). TBARS value of 2 days was significantly lower in 4 and $6\%$ RVS treatments than in control (p<0.05) but it was significantly lower in $4\%$ RVS treatment than the other treatments from 5 days (p<0.05). Surface MetMb concentration was significantly lower in RVS treatment than in control during storage (p<0.05) and it was significantly lower in $4\%$ RVS treatment than in the other treatments in 7days (p<0.05) but surface $R_{6.30}/R_{580}$ value was opposite to this result.

• Communications for Statistical Applications and Methods
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• v.16 no.4
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• pp.579-586
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• 2009

We have used multifactor dimensionality reduction(MDR) method to study interaction effect of statistical model in general. But MDR method cannot be applied in all cases. It can be applied to the only case-control data. So, two methods are suggested E-MDR and D-MDR method using regression tree algorithm and dummy variables. We applied the methods on the identify interaction effects of single nucleotide polymorphisms(SNPs) responsible for longissimus mulcle dorsi area(LMA), carcass cold weight(CWT) and average daily gain(ADG) in a Hanwoo beef cattle population. Finally, we compare the results using permutation test.

• Journal of Animal Science and Technology
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• v.65 no.4
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• pp.865-877
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• 2023

Thirty Hanwoo cattle including bulls, cows, and steers (n = 10 each) were slaughtered and investigated for carcass traits (weight, meat color, fat color, yield index, maturity, marbling score, back-fat thickness, and firmness) and meat quality. The meat quality such as: pH, color, cooking loss, fatty acid, thiobarbituric acid reactive substance, warner-bratzler shear force, tensile tests, and texture profiles were analyzed on longissimus lumborum (LL) muscles of the carcasses at different aging times (3 d and 21 d). The results showed that steers and cows had higher back-fat thickness and marbling score, and a lower firmness (p < 0.001) than bulls. Bulls exhibited a lower meat quality indicating by higher cooking loss, thiobarbituric acid reactive substance content, warner-bratzler shear force and tensile test values (p < 0.01). Regarding the sensory property, the bull meat also had higher hardness, and lower tenderness, juiciness and flavor scores than the cow or steer meat (p < 0.01). Additionally, the bull meat had a higher polyunsaturated fatty acid and a lower monounsaturated fatty acid contents (p < 0.01). With increased aging time, the meat tenderness was improved in all the genders. Taken together, the present study demonstrated that the gender and aging time affected the carcass traits, fatty acid and sensory quality of beef. Postmortem aging could improve the meat tenderness of all genders especially bulls.

• Journal of Life Science
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• v.27 no.4
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• pp.464-470
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• 2017

Three Korean native cattle (KNC) and seven exotic breeds (Chikso, Hanwoo, Jeju black, Holstein, Japanese black, Charolais, Angus, Hereford, Simmental, and Cross breed) were characterized by using five microsatellite (MS) markers (INRA30, TGLA325, UMN0803, UMN0905, and UMN0929) from the sex chromosome. Genetic diversity was evaluated across the 10 breeds by using the number of alleles per locus, allele frequency, heterozygosity, and polymorphism information content (PIC) to search for locus and/or breed specific alleles, allowing a rapid and cost-effective identification of cattle samples, avoiding mislabeling of commercial beef. It was divided into two main groups from STRUCTURE analysis, one corresponding to KNC and the other to exotic cattle breeds. These results also showed specific genetic differences between KNC and exotic breeds. Nei's standard genetic distance was calculated and used in the construction of a neighbor-joining tree. Results evidenced a correspondence between genetic distance, breeds' history, and their geographic origin, and a clear separation between KNC and exotic breeds. Overall, this study evidenced that DNA markers can discriminate between domestic and imported beef, contributing to the knowledge on cattle breeds' genetic diversity and relationships by using MS markers of the sex chromosome. These markers would be useful for inhibitory effect about false sales and for building an effective tracking system.

• Korean Journal of Agricultural Science
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• v.47 no.4
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• pp.1109-1122
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• 2020

The aim of this study was to develop a marbling classification and prediction model using small parts of sirloin images based on a deep learning algorithm, namely, a convolutional neural network (CNN). Samples were purchased from a commercial slaughterhouse in Korea, images for each grade were acquired, and the total images (n = 500) were assigned according to their grade number: 1++, 1+, 1, and both 2 & 3. The image acquisition system consists of a DSLR camera with a polarization filter to remove diffusive reflectance and two light sources (55 W). To correct the distorted original images, a radial correction algorithm was implemented. Color images of sirloins of Hanwoo (mixed with feeder cattle, steer, and calf) were divided and sub-images with image sizes of 161 × 161 were made to train the marbling prediction model. In this study, the convolutional neural network (CNN) has four convolution layers and yields prediction results in accordance with marbling grades (1++, 1+, 1, and 2&3). Every single layer uses a rectified linear unit (ReLU) function as an activation function and max-pooling is used for extracting the edge between fat and muscle and reducing the variance of the data. Prediction accuracy was measured using an accuracy and kappa coefficient from a confusion matrix. We summed the prediction of sub-images and determined the total average prediction accuracy. Training accuracy was 100% and the test accuracy was 86%, indicating comparably good performance using the CNN. This study provides classification potential for predicting the marbling grade using color images and a convolutional neural network algorithm.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.1
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• pp.45-50
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• 2002

This experiment was conducted to establish the intensive Grazing system through the improved pasture utilization of the Hanwoo beef cattle. Intensive grazing period, 2 to 3 days was compared to conventional rotation-grazing period, 5 to 6 days as control. The intensive grazing system which has 2 to 3 days of grazing period, increased forage DM yield(7.33t/ha) by 17% compared to control(6.28t/ha), and contributed to stabilization of the seasonal productivity through the increased DM yield after August. Plant height, feed intake and efficiency of grazing was increased in intensive rotation.