• Asian-Australasian Journal of Animal Sciences
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• v.33 no.10
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• pp.1656-1665
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• 2020

Objective: This study aimed to determine the effects of stress during slaughter of beef cattle on physiological parameters, carcass, and meat quality at a Federal Inspection Type slaughterhouse located in the southeast of Mexico. Methods: A total of 448 carcasses of male Zebu×European steers with an average age of 36 months were included. Carcass assessment of presence of bruises and bruise characteristics was carried out on each half-carcass. Blood variable indicators of stress (packed cell volume, neutrophil to lymphocyte ratio, glucose, cortisol concentration) and meat quality parameters (pH, color, shear force, drip loss) were evaluated. Results: Of the 448 carcasses evaluated, 81% of the carcasses showed at least one bruise; one bruise was detected in 36.6% and two bruises in 27.0% of animals. Of the 775 bruises found, 69.2% of the bruises were grade 1 in region 3. Of the 448 carcasses studied, 69.6% showed hyperglycemia (6.91 mmol/L); 44.3% and 22.7% showed high (74.7 ng/mL) and extremely high (108.8 ng/mL) cortisol levels, respectively, indicative of inadequate handling of animals during preslaughter and slaughter. Of the carcasses evaluated, 90.4% had a pH ≥5.8 with an average of pH 6.3. In both pH groups, meat samples showed L^⋆ values >37.0 (81.6%) and a shear force >54.3 N; meat pH≥5.8 group showed a drip loss of 2.5%. These findings were indicative of dark, firm, and dry (DFD) meat. According to principal component analysis, grades 1 and 2 bruises in region 3 and grade 1 bruises in region 5 were highly associated with cortisol, drip loss, and color parameters b^⋆ and h^⋆ and were negatively associated with L^⋆, a^⋆, and C^⋆. Conclusion: The bruises probably caused by stress-inducing situations triggered DFD meat. Appropriate changes in handling routines in operating conditions should be made to minimize stress to animals during the slaughter process to improve animal welfare and meat quality.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.12
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• pp.1974-1979
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• 2018

Objective: This study compared fatty acid compositions and antioxidant activities of high-preference cuts (loin, tenderloin, and rib) and low-preference cuts (brisket, topside, and shank) of Hanwoo (Bos taurus coreanae) cows to obtain potentially useful information for promoting the consumption of various low-preference cuts. Methods: Individual 500 g samples of fresh beef were collected from each of the six cuts from 10 Hanwoo cows (quality grade 1) and immediately freeze-dried. The dried samples were evaluated for fatty acid composition, free radical scavenging activities (hydroxyl, alkyl, and 2, 2'-diphenyl-1-picrylhydrazyl [DPPH] radical), and antioxidative enzyme activities (glutathione peroxidase [GPx], glutathione-S-transferase [GST], and superoxide dismutase [SOD]). Results: The percentages of total polyunsaturated fatty acids were significantly higher in low-preference cuts than in high-preference cuts (p<0.05). Hydroxyl, alkyl, and DPPH radical scavenging activities were significantly higher in low-preference cuts than in high-preference cuts (p<0.05). In addition, the activities of antioxidant enzymes, such as GPx, GST, and SOD, were significantly higher in low-preference cuts compared with high-preference cuts (p<0.05). Conclusion: These results may influence consumers to include more low-preference cuts in their selections based on the nutritional facts, which could help to balance the beef market in South Korea.

• Journal of The Korean Society of Grassland and Forage Science
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• v.30 no.3
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• pp.257-266
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• 2010

This study was carried out to investigate the effect of feeding whole crop barley silage (WBS) on the growth performance, gain, feed requirement, carcass grade and beef quality of Hanwoo steers in 1999 to 2001. Twenty one steers were allocated, and divided into three treatment groups which fed rice straw only (control), WBS only, and fresh rice straw silage plus WBS during overall period ad libitum. Concentrates were fed at 1.5% level of live-body weight during growing stages, 4~12 months of age, at 1.8% level of live-body weight during early fattening stages, 13~18 months of age, and ad libitum after late fattening stages, 19~27months of age. The production yields of WBS were 17,135 kg as a silage, and 6,011 kg as a dry matter per ha, and the quality of WBS was 2~3 grade, while that of rice straw silage was 4grade. The daily gain with feeding of WBS (0.70 kg) during experimental period was higher than that of control group (0.65 kg), and the concentrate requirement (7.31 kg) per kg gain in WBS was lower than that of control (8.95 kg). The effects of gain and feed efficiency were very distinct during growing stage. i.e., the daily gain of WBS (0.84 kg) was increased by 65% compared to control (0.51 kg), and the concentrate requirement (4.16 kg) per kg gain in feeding of WBS was decreased by 35%, compared to control (6.39 kg). Meat quality with WBS was higher than that of control. Frequency rate of 1 and/or $1^+$ grade, and marbling score of feeding of WBS were 62.5% and 4.38, while those of control were 37.5% and 2.75, respectively. The results of the sensory evaluation showed that Hanwoo beef fed with WBS were better than that of control. In conclusion, feeding of WBS was desirable to improve daily gain, reduction of concentrates, feed efficiency and meat quality of Hanwoo steers.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.7
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• pp.1202-1208
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• 2020

Objective: The aim of this study was to identify a distribution pattern of meat quality grade (MQG) as a function of carcass yield index (CYI) and the gender of Hanwoo (bull, cow, and steer) to determine the optimum point between both yield and quality. We also attempted to identify how pre- and post-deboning variables affect the gender-specific beef quality of Hanwoo. Methods: A total of 31 deboning variables, consisting of 7 pre-deboning and 24 post-deboning variables from bulls (n = 139), cows (n = 69), and steers (n = 153), were obtained from the National Institute of Animal Science (NIAS) in South Korea. The database was reconstructed to be suitable for a statistical significance test between the CYI and the MQG as well as classification of meat quality. Discriminant function analysis was used for classifying MQG using the deboning parameters of Hanwoo by gender. Results: The means of CYI according to 1+, 1, 2, and 3 of MQG were 68.64±2.02, 68.85±1.94, 68.62±5.88, and 70.99±3.32, respectively. High carcass yield correlated with low-quality grade, while high-quality meat most frequently was obtained from steers. The classification ability of pre-deboning parameters was higher than that of post-deboning parameters. Moisture and the shear force were the common significant parameters in all discriminant functions having a classification accuracy of 80.6%, 71%, and 56.9% for the bull, cow, and steer, respectively. Conclusion: This study provides basic information for predicting the meat quality by gender using pre-deboning variables consistent with the actual grading index.

• Food Science of Animal Resources
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• v.41 no.1
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• pp.45-58
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• 2021

This study investigated the dietary effect of total mixed ration (TMR) based on high roughage content on the growth performance, carcass characteristics, and meat quality of Hanwoo steers. Twenty-four Hanwoo steers (average body weight, 195.3±4.7 kg; age, 8.5 mon) were randomly allocated to three experimental groups according to forage and concentrate ratio (DM basis): 25:75 (control), 50:50 (T50), and 70:30 (T70). Productivity in the fattening period and final body weight were significantly higher in the control. Average daily gain and feed conversion ratio were the same among treatments. Serum parameters, cholesterol, blood urea nitrogen, and total protein were higher in the control. Carcass weight was comparable in the control and T50 but feeding more roughage was significantly correlated with a higher intramuscular fat. Shear strength and drip loss were higher while n-6/n-3 was lower in T70 compared to the other groups. However, meat color was not significantly different among treatments. In terms of free amino acid contents, glutamic acid and glycine were higher in the control than T50 and T70. Overall, feeding Hanwoo steers with high forage content TMR had the lowest n-6/n-3 ratio of fatty acid content but highest intramuscular fat, shear strength, and drip loss. High forage content TMR is the best feed for Hanwoo steers that gives more benefits for human health and consumption but also provides the best meat grade and quality, which is important in the beef market in Korea.

• 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.20 no.2
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• pp.194-199
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• 2007

Effects of recombinant bovine somatotropin (bST) on plasma hormonal concentration, embryo quality, and pregnancy rate were examined during the superovulation and synchronization treatment in donor and recipient cows. Hanwoos (Korean native beef cattle) were treated with controlled internal drug release (CIDR) combined with bST (CIDR+bST) or without bST (CIDR) as donor cows. The embryos recovered from donors were transferred into Holstein recipient heifers treated with bST (CIDR+bST) or without bST (CIDR) for synchronization. The correlation between IGF-I and P4 showed a positive pattern in the CIDR+bST group (r=0.44, p<0.01), but a negative pattern was shown in the CIDR group (r = -0.59, p<0.02) at day 7 of estrous cycles. Although the number of recovered, transferable, and degenerated embryos was not different, quantities of grade 1 (excellent) embryos in CIDR+bST group were significantly higher than those of the CIDR group (p<0.01). The pregnancy rate was higher in the CIDR+bST recipient group compared to CIDR group (p<0.05), when the embryos were recovered from the donors treated with CIDR. However, the pregnancy was maintained highly in both recipient groups, when the embryos were produced by CIDR+bST treated donors. It can be concluded that bST administration combined with CIDR is an effective method for superovulation and synchronization treatment to stabilize plasma hormonal levels, to obtain excellent quality of embryos, and to get higher pregnancy rate.

• Food Science of Animal Resources
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• v.37 no.4
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• pp.593-598
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• 2017

The objective of this study was to determine the influence of quality grade (QG) on meat tenderness characteristics of ten major muscles from Hanwoo steers. A total of 25 Hanwoo carcasses ($5\;carcasses{\times}5\;QGs$) were selected. Intramuscular fat content, collagen content, sarcomere length, and Warner-Bratzler shear force (WBSF) of Longissimus thoracis (LT), Longissimus lumborum (LL), Psoas major (PM), Semisponals (SS), Triceps brachii (TB), Semimembranosus (SM), Gluteus medius (GM), Rectus Abdominis (RA), Superficialis flexor (SF), and Internal and external intercostal (IC) were determined. IC had the highest fat content, followed by LT, RA, LL, PM, GM, SS, SF, TB, and SM. High-fat muscles such as LT, LL, IC, RA, and PM had significantly (p<0.05) different fat contents among QGs. Collagen contents were significantly (p<0.05) different among QGs. With decreasing QG, increasing collagen content was found in muscles. There were significant (p<0.05) differences in sarcomere length among QGs of several muscles. However, no significant (p>0.05) difference in sarcomere length was found among QGs for LL, PM, or RA muscle. PM had the lowest WBSF, followed by LL, LT, RA, IC, GM, SM, SF, SS, and TB. WBSF of QG $1^{{+}{+}}$ was lower than that of QG 1 for SS, TB, and SM. All muscles of QG 1 showed lower WBSF than QG 3 except TB or IC. Results of this study suggested that differences in WBSF among these 10 muscles by QG were due to differences in collagen content and sarcomere length.

• Journal of Animal Science and Technology
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• v.45 no.4
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• pp.585-592
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• 2003

The current study was conducted to determine the relationships of vitamin A on meat quality of Hanwoo as a basic study to manipulate vitamin A contents in feeds to produce high quality beef. Concentrations of vitamin A in serum and liver of Hanwoo steers(n=328) were analyzed and correlation coefficients with carcass properties were evaluated. Mean vitamin A concentration in the serum of Hanwoo steers in the early fattening period was 212.0$\pm$32.7 IU/dl, and that in the late fattening period was 117.56$\pm$43.15 IU/dl. Mean vitamin A concentration in the liver of Hanwoo steers in the late fattening period was 143.62$\pm$110 IU/g expressing large variations might be depended on animals, feeds and farms. There were negative correlations between serum vitamin A concentration and marbling degree(r=-0.24, P<0.01), fat contents in M. Logissimus dorsi (r=-0.21, P<0.01), and beef quality grade(r=-0.20, P<0.01). Vitamin A-palmitate in liver also expressed negative correlations with fat contents in M. Logissimus dorsi (r=-0.18, P<0.01) and beef quality grade(r=-0.16, P<0.05). From the results obtained in the current study, we concluded that it might be possible to produce high quality beef in Hanwoo by manipulating vitamin A contents in the feeds. Further detailed studies, however, are necessary to determine vitamin A contents in feeds, feeding levels, and feeding periods.

• Korean journal of food and cookery science
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• v.26 no.4
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• pp.347-357
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• 2010

This study was assessed the menu satisfaction and preferences of high school boarding students in Gyeongggido. Data collection was carried out through surveys given to 300 high school boarding students; a total of 274 were usable. Statistical analyses were done using the SAS package program (version 8.2 for Windows). The results of this study are summarized as follows: 54.0% of respondents were freshman and 46.0% were sophomores: and 52.9% of respondents were male and 47.1% were female. According to the results of the menu satisfaction survey, males and females significantly differed on appropriate food temperature, freshness of food, harmonic combination of menu, menu variety, quality of ingredients, appearance of food, and frequency of supplied nutrition information. A significant difference regarding menu satisfaction was also found between grade level. First grade students were more satisfied than second grade students. Moreover, menu preferences were significantly high for omelet-rice, fried rice, pork-on-the-bone soup, deep-fried chicken, fruit salad, spicy chinese cabbage salad kimchi, chinese cabbage kimchi, and all desserts. On the other hand, pumpkin and rice porridge, beef and rice porridge, barley rice, soft tofu stew, soybean paste soup, braised japanese spanish mackerel, and sauteed squash were not significantly preferred. The results showed that high school boarding students' menu preferences differed depending on gender, grade, and boarding period. In conclusion, the results of this study should provide dieticians information for improving menu planning. In addition, foodservice satisfaction of the boarding school students can be improved by continuous menu improvement.