• Asian-Australasian Journal of Animal Sciences
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• v.33 no.7
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• pp.1087-1095
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• 2020

Objective: The present study aimed to evaluate the effects of γ-aminobutyric acid (GABA)-producing bacteria (GPB) on in vitro rumen fermentation and on the growth performance and meat quality of Hanwoo steers. Methods: The effects of GPB (Lactobacillus brevis YM 3-30)-produced and commercially available GABA were investigated using in vitro rumen fermentation. Using soybean meal as a substrate, either GPB-produced or commercially available GABA were added to the in vitro rumen fermentation bottles, as follows: control, no additive; T1, 2 g/L GPB; T2, 5 g/L GPB; T3, 2 g/L autoclaved GPB; T4, 5 g/L autoclaved GPB; T5, 2 g/L GABA; and T6, 5 g/L GABA. In addition, 27 Hanwoo steers (602.06±10.13 kg) were subjected to a 129-day feeding trial, during which they were fed daily with a commercially available total mixed ration that was supplemented with different amounts of GPB-produced GABA (control, no additive; T1, 2 g/L GPB; T2, 5 g/L GPB). The degree of marbling was assessed using the nine-point beef marbling standard while endotoxin was analyzed using a Chromo-Limulus amebocyte lysate test. Results: In regard to in vitro rumen fermentation, the addition of GPB-produced GABA failed to significantly affect pH or total gas production but did increase the ammonia nitrogen (NH₃-N) concentration (p<0.05) and reduce total biogenic amines (p<0.05). Animals fed the GPB-produced GABA diet exhibited significantly lower levels of blood endotoxins than control animals and yielded comparable average daily gain, feed conversion ratio, and beef marbling scores. Conclusion: The addition of GPB improved in vitro fermentation by reducing biogenic amine production and by increasing both antioxidant activity and NH₃-N production. Moreover, it also reduced the blood endotoxin levels of Hanwoo steers.

• Journal of the Korean Data and Information Science Society
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• v.22 no.4
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• pp.661-669
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• 2011

By direct sequencing of 12 STS marker, we identified 10 polymorphic SNPs. As a result of genotype frequency analysis between 10 polymorphic SNPs and extreme population (n=20) for marbling score in Hanwoo (n=233), there was over 40 percent of frequency difference of HWSNP_1-1 and HWSNP_9-4 SNP. HWSNP_1-1 SNP was significantly associated with marbling score in large-scale population (n=233). Therefore we suggested that HWSNP_1-1 SNP can be useful as a positional candidate for beef quality for marker-assisted selection in Hanwoo.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.8
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• pp.1083-1094
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• 2016

Carcass and price traits of 72,969 Hanwoo cows, bulls and steers aged 16 to 80 months at slaughter collected from 2002 to 2013 at 75 beef packing plants in Korea were analyzed to determine heritability, correlation and breeding value using the Multi-Trait restricted maximum likelihood (REML) animal model procedure. The traits included carcass measurements, scores and grades at 24 h postmortem and bid prices at auction. Relatively high heritability was found for maturity ($0.41{\pm}0.031$), while moderate heritability estimates were obtained for backfat thickness ($0.20{\pm}0.018$), longissimus muscle (LM) area ($0.23{\pm}0.020$), carcass weight ($0.28{\pm}0.019$), yield index ($0.20{\pm}0.018$), yield grade ($0.16{\pm}0.017$), marbling ($0.28{\pm}0.021$), texture ($0.14{\pm}0.016$), quality grade ($0.26{\pm}0.016$) and price/kg ($0.24{\pm}0.025$). Relatively low heritability estimates were observed for meat color ($0.06{\pm}0.013$) and fat color ($0.06{\pm}0.012$). Heritability estimates for most traits were lower than those in the literature. Genetic correlations of carcass measurements with characteristic scores or quality grade of carcass ranged from -0.27 to +0.21. Genetic correlations of yield grade with backfat thickness, LM area and carcass weight were 0.91, -0.43, and -0.09, respectively. Genetic correlations of quality grade with scores of marbling, meat color, fat color and texture were -0.99, 0.48, 0.47, and 0.98, respectively. Genetic correlations of price/kg with LM area, carcass weight, marbling, meat color, texture and maturity were 0.57, 0.64, 0.76, -0.41, -0.79, and -0.42, respectively. Genetic correlations of carcass price with LM area, carcass weight, marbling and texture were 0.61, 0.57, 0.64, and -0.73, respectively, with standard errors ranging from ${\pm}0.047$ to ${\pm}0.058$. The mean carcass weight breeding values increased by more than 8 kg, whereas the mean marbling scores decreased by approximately 0.2 from 2000 through 2009. Overall, the results suggest that genetic improvement of productivity and carcass quality could be obtained under the national scale breeding scheme of Korea for Hanwoo and that continuous efforts to improve the breeding scheme should be made to increase genetic progress.

• Journal of the Korean Dietetic Association
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• v.23 no.2
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• pp.129-142
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• 2017

The purpose of this study was to compare the usage of beef and foodservice managers' perceptions of beef quality by foodservice type. A survey was conducted on 546 dietitians, and 499 acceptable responses were used for data analysis. By weight, pork was the most used meat in foodservice institutions, followed by poultry and beef. More than half of the foodservices selected meat suppliers by competitive bidding. Approximately 85.8% of the respondents used Hanwoo beef, followed by Australian beef and Youku beef. Beef type differed significantly by foodservice type (P<0.001): most of the schools and social welfare facilities used Hanwoo beef, whereas most hospitals and business/industry operations used Australian beef. When purchasing beef, safety of beef was rated the most important, while eco-friendliness was rated the least important. Most of the dietitians understood that marbling is one of the determinants of the beef quality, but were not aware of other components. Dietitians that selected Hanwoo and Youku beef were more satisfied with quality, taste, nutrition, freshness, country of origin, package, customer, preference, and availability for various menus than those who used imported beef. Dietitians who used Hanwoo beef were the most satisfied with country of origin, whereas the others were the most satisfied with safety. Since the dietitians are in charge of planning menus and selecting meat suppliers at foodservice institutions, they should make knowledgeable decisions by understanding meat supply systems and quality of beef.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.7
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• pp.968-975
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• 2018

Thailand is a country of native beef cattle resource farming. It has undergone rapid social and economic change in the past decade. Agricultural growth has been maintained by increasing the production of rice and cassava. Changing economic status also provides opportunities for beef cattle producers to meet increasing consumer demand for beef. Finishing beef cattle numbers in Thailand were about 1.0 M head in 2015. Beef produced in Thailand has exclusively been for domestic consumption. Only 1% of Thailand's beef cattle are for the premium market which is based on marbling score, 40% are sold into modern markets that consider muscling of cattle, and the remainder enter traditional markets. Cross-bred cattle for the premium market are raised within intensive systems. Most producers of premium beef are members of beef cooperatives, or have invested in their enterprises at high levels. Culled cow (native or cross-bred cattle) are mainly for small holder farm production. Malaysia, Indonesia, and other members of the Asian Economic Community (AEC) are set to become the largest beef market, which has been confirmed by 2015 through 2020 forecasts for consumption of beef that must increasingly be halal. These circumstances are likely to be challenging for beef producers in Thailand to gain a share of this market. Integration across all sectors involved in beef production in Thailand will be required.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.7
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• pp.1036-1042
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• 2018

Meat quality is a very difficult term to define because it means different things to different people. When purchasing beef, consumers in the United States are likely to consider color, price, marbling level, subcutaneous fat trim, or cut thickness when determining the quality of beef. Once consumers have consumed the product, meat quality becomes exponentially more difficult to define due to the subjective nature of this term. Traditionally, tenderness, juiciness, and flavor have been considered the three most important factors that determine the palatability of beef. Therefore, American meat science beef research and industry focus has turned to measuring and quantifying these 3 attributes objectively and subjectively, and to determining what influences them. In reviewing the scientific literature, attempting to meaningfully summarize the findings of the thousands of studies on beef meat quality is impossible due to the inherent differences in the objective and methodology of studies. Fortunately, the United States beef industry and their national trade association, the National Cattlemen's Beef Association (NCBA), have conducted numerous surveys and audits to characterize the quality of the products being produced and marketed by their cattlemen and the palatability perceptions of their consumers. The data produced by these studies is quite large and impossible to summarize in entirety in this review. Therefore, this review concentrates on the most important attributes that determine the value of a beef carcass and objectively measured and consumer-assessed palatability characteristics of fresh meat from these carcasses from 1987 through 2010.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.1
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• pp.123-135
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• 2001

Application of growth promoters by means of implantation or supplementation to the diets has been routine in the beef cattle industry of many countries for the better performance in growth and improvement of feed efficiency. Anabolic implants (zeranol, trenbolone acetate, and estradiol with testosterone or progesterone) have generated various positive effects. Zeranol implantation, in general, improved average daily gain (ADG), feed conversion (FC), dressing percentage (DP) and yield grade (YG) of cattle, and increased dry matter intake (DMI). Trenbolone acetate with or without estradiol also increased mean values of ADG and loin eye area (LEA) but reduced DMI and improved FC of cattle. Estradiol with testosterone or progesterone increased ADG and DMI. Anabolic implants, however, had minimal or negative effects on marbling or quality grade. The magnitude of the response to these anabolic implants in performance of beef cattle has varied depending on the type of implants, amount and duration of exposure, age of animals and combination of implants. Administration of bovine somatotropin improved ADG and FC, and decreased fat deposition. Ionophores improved FC in cattle from reduced DMI without great response to ADG. Supplementation of monensin and lasalocid reduced molar proportion of propionate. Monensin and lysocellin increased apparent absorption and retention of some minerals in cattle. Despite the improved cattle performance in growth and FC, results in beef quality from the application of the growth promoters appeared to vary or in conflict under a variety of environmental conditions.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.2
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• pp.172-177
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• 2007

Thyroid hormones play an important role in regulating metabolism and can affect homeostasis of fat depots. The gene encoding thyroglobulin (TG), producing the precursor for thyroid hormones, has been proposed as a positional and functional candidate gene for a QTL with an effect on fat deposition. The SNP occurs in the 5' promoter region of the TG gene and is widely used in marker assisted selection (MAS) programs to improve the predictability of marbling level and eating quality in beef cattle. In this study, we identified three SNPs at the 5' promoter region of the TG gene in Korean cattle. Of the three SNPs identified in TG gene, the C257T and A335G were previously unreported new SNPs. The sequence data were submitted to GenBank (GenBank accession number: AY615525). The previously reported C422T SNP showed three genotypes, CC, CT and TT, by digestion with the restriction enzyme MflI using the PCR-RFLP method. A new allelic variant corresponding to the C${\rightarrow}$T and A${\rightarrow}$G mutations at positions 257 and 335, respectively, could be detected by the SSCP analysis. The gene-specific SNP marker association analysis indicated that the C422T SNP marker was significantly associated (p<0.05) with marbling score. Animals with the CC and CT genotypes had higher marbling score than those with the TT genotype. Results from this study suggest that TG gene-specific SNP may be a useful marker for meat quality traits in future MAS programs in Korean cattle.

• 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.