• Journal of Life Science
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• v.21 no.10
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• pp.1460-1465
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• 2011

This study was conducted to determine the effects of total mixed fermentation (TMF) with bean curd dregs on body weight gain, feed intake and body size of growing Hanwoo heifers. Thirty Hanwoo heifers, 6 months of age and weighing $125.9{\pm}12.0$ kg, were randomly allocated to 3 experimental groups of 10 animals each for a 6-month feeding trial. The groups were T1 (rice straw offered ad libitum with restricted (1.7% BW/day) concentrate), T2 (TMF only offered ad libitum) and T3 (TMF and rice straw offered ad libitum with restricted (1.0% BW/day) concentrate). TMF feeds were composed of 60% bean curd dregs, 16.5% corn meal, 10.4% wheat bran, 5% rice straw, 7% rice hulls, 0.5% urea matter, 0.5% magnesia lime and 0.1% lactic acid bacteria. The chemical composition and pH value of TMF feeds were measured at 0, 24, 48 and 72 hr after storage. In TMF with bean curd dregs, there were no differences in concentrations of DM, EE, and CF according to storage periouds. The ADF and NDF at 72 hr of storage time showed a significant decrease (9.52 and 3.15 %, respectively) compared to 0h of storage time (p<0.05). The value of pH was gradually decreased during the storage periods. Body weight gain, feed intake and average daily gain were higher in the TMF groups (T2, T3) compared to the T1 group (p<0.05). Changes in body size were also higher in the TMF groups compared to the T1 group (p<0.05). Thus, the present results indicate that TMF with bean curd dregs may help improve growth performance in growing Hanwoo heifers.

• Food Science of Animal Resources
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• v.27 no.3
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• pp.277-283
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• 2007

This study was conducted to determine the effect of mugwort powder supplementation on the fattening performance and carcass characteristics during a 14 month period (from 14 months to 27 months after birth) in 32 heads of fattening Hanwoo. Fattening Hanwoos were randomly assigned 4 treatments (8 heads/treatment): C-1 [(control (0%) with Hanwoo steers)], C-2 [(control (0%) with Hanwoo heifers)], T-1 (supplementation with 2.0% mugwort powder with Hanwoo steers) and T-2(supplementation with 2.0% mugwort powder with Hanwoo heifers). The final body weights for C-1, C-2, T-1 and T-2 at 27 months were 648.6kg, 623.1kg, 663.3kg and 620.7kg, respectively. The total gain and the daily gain were highest in the T-1 group (342.4 kg, 0.88 kg). Hanwoo steers were not significantly different from Hanwoo heifers. The feed intake for the C-1, C-2, T-1 and T-2 groups were 9.35 kg, 9.09 kg, 10.08 kg and 9.69 kg, with the T-1 value being highest. The feed conversion ratios were as follows: C-1 (11.28) > T-1 (11.48) > C-2 (11.52) > T-2 (12.57). The concentrations of total cholesterol, GOT, GPT, glucose and BUN in blood serum during the fattening period were higher after than before the experiment The total cholesterol, GOT and glucose after completion of the experiment were higher in the treatment groups than the control groups (p<0.05). The carcass body weight was higher in the treatment groups than the control groups. The back fat thickness was lower in the treatment groups (12.75-14.75mm) than the control groups (15.76-16.00mm), and the longissimus muscle area was higher in the treatment groups $(84.25-87.88cm^2)$ than the control groups $(84.00-85.25cm^2)$ with the highest over-all values in the T-1 group (p<0.05). The yield grade and quality grade point were higher in the treatment groups (2.02-2.50, 2.85-3.05 point, respectively) than the control groups (1.80, 2.55-2.80 point, respectively). In conclusion, the effects of feeding dietary mugwort powder to Hanwoo steers improved the ADG, carcass body weight, longissimus muscle area and quality grade.

• Journal of Embryo Transfer
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• v.31 no.3
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• pp.261-265
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• 2016

The aim of the present study was to evaluate and estimate timing of artificial insemination (AI) in Hanwoo heifer (Korean native cattle) that is the most popular breed of beef cattle in Korea. To determine changes in body weight of heifers around AI, body weight were measured at different stages either before or after AI. We found that daily body weight gain was higher in the pregnant cows after AI. We also investigate correlation between body mass measured by shoulder height and body length, and conception rates, used (body length+ height)2 instead of height2 for body mass index (BMI), and found that relatively more BMI heifers (>55) showed higher conception rates. Finally, we estimated body weight by measuring should height (SH), heart girth (HG), and body length (BL); $BW=3.93372^*HG-2.90985^*SH-0.021^*BL$. In addition, we observed that HG is most closely correlated with BW; $y(BW)=1.77355^*x(HG)$, $R^2=0.98881$. In summary, we can determine the best timing of AI using body measurement and its application including BMI.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.10
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• pp.1691-1698
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• 2020

Objective: The study sought to estimate the relationship between body surface temperature (BST) and temperature humidity index (THI) and to present the validity of THI as a heat stress index in the field. Methods: Eight Hanwoo heifers (20 to 32 month) were examined in a field trial, with a space allowance of 10 ㎡ per head. The BST was measured using an infrared thermographic camera. The BST of five body regions (eyes, hindquarters, nose, part of horns, and ears), ambient temperature (AT), and relative humidity (RH) were measured 7 times daily (07, 09, 11, 13, 15, 17, and 19 h) during each season with three replicates. Results: The THI ranged 34.0 to 56.9 during spring (AT, -1.0℃ to 13.4℃), 75.1 to 84.7 during summer (AT, 24.9℃ to 33.6℃), 55.8 to 70.9 during autumn (AT, 13.0℃ to 26.0℃) and 17.5 to 39.2 during winter (AT, -10.4℃ to 1.0℃). In the regression analysis, the coefficient of determination (R²) between THI and BST was 0.88, 0.72, 0.83, 0.86, and 0.85 for the eyes, hindquarters, nose, part of horn, and ears area, respectively. This indicates that BST has a strong correlation with AT and RH. Expression equations were estimated as Y (THI) = 31.54+0.1085X (BST of eyes) and Y (THI) = 30.48+0.1147X (BST of hindquarters) by simple linear regression analysis in this experiment. Conclusion: Consequently, the upper bound for heat stress estimation can be specified ranging from THI of 65 (eyes) to 70 (hindquarters). From this we can expect a precise feeding system for Korean native cattle in the field.

• Journal of Animal Science and Technology
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• v.61 no.1
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• pp.41-46
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• 2019

Different methodologies in hair cortisol extraction may alter the final output. Thus finding the standard methodology according to a laboratory facilities is pivotal. This study was carried out to validate the feasibility of two methods of grinding hair for cortisol extraction in Korean native (Hanwoo) cattle. Hair from nine cattle including mature cows, heifers, and calves were assigned to one of the following methods for grinding hair; 1) using bead beater (BB) and 2) using surgical scissors (SS). Hair samples (> 1 g) were harvested from forehead of each individual twice (first and second measurement) to validate the results. To improve the accuracy of the obtained data, each sample was duplicated into two wells during enzyme immunoassay (EIA) analysis. Overall comparison of hair cortisol concentration (HCC) showed that the data within the range (out of the range) of standards provided by the EIA kit were 88.9% (11.1%) and 66.7% (33.3%) for BB compared with SS, respectively. In the first measurement, application of BB was tended to show higher (p = 0.056) amount of HCC compared with SS. In the second measurement application of BB showed higher (p = 0.0028) amount of HCC compared with SS. Among the cattle, calves showed higher HCC using BB compared with SS (p < 0.05). Application of BB in hair grinding methodology for Hanwoo cattle may improve cortisol extraction in comparison to application of SS method, with more consistency. Thus, it would be the preferable method to use.

• Journal of Animal Science and Technology
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• v.66 no.3
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• pp.614-629
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• 2024

Hanwoo beef is in high demand because of its unique flavor, freshness, and high-fat content. However, the longer rearing period required to enhance marbling in Hanwoo cattle has adverse environmental consequences, such as greenhouse gas emissions and overall rearing costs. To address consumer preferences for leaner and healthier meat, the Korean meat industry has recently introduced Hanwoo heifer meat as an alternative source, but its quality traits are still unclear. Nevertheless, there is a limited body of research exploring the impact of Hanwoo gender (steer, heifer, and cow) and their corresponding slaughter ages on meat quality traits. This study looked into how gender affected the physicochemical and qualitative features of Hanwoo striploin at their respective slaughter ages. Results revealed that cow striploin has higher levels of moisture (66.81%) and protein (20.76%), whereas it contains lower levels of fat (10.66%) and cholesterol (34.66 mg/100 g). Regarding the physicochemical properties, cow striploin exhibited significantly lower shear force, color indexes, and soluble collagen (p < 0.05). However, chondroitin (1.19%) and muscle fiber area (1,545.23 ㎛²) were significantly higher in steer striploin than in heifer and cow (p < 0.05). Cow striploin exhibited significantly higher levels of oleic acid, unsaturated fatty acids (UFAs), and monounsaturated fatty acids (MUFAs) while having lower levels of eicosadienoic acid and atherogenic index compared to the other two groups. Cows and heifers had higher concentrations of amino acid metabolites than striploin from steers. Furthermore, bioactive metabolites such as carnitine and carnosine content were found higher in cow and heifer respectively. Overall, Hanwoo cattle gender influences the qualitative attributes of striploin; nevertheless, compared to steer and heifer striploin, cow striploin is a relatively good source of protein, fatty acid content, and metabolites conducive to a healthy diet.

• Journal of Animal Science and Technology
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• v.47 no.4
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• pp.593-606
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• 2005

Present study was conducted to investigate the optimal feeding levels for producing the high quality meat on the basis of the information deriving from the comparison of the growth performance and carcass characteristics among breeds(Holstein vs F1, Holstein♀×Hanwoo♂), sex(steer vs heifer) and interaction between breed and sex. Thirty two animals on 4 treatments(i.e. eight head each) were used for 540 days from seven to 24 months of age. The results obtained are summarized as follows; the range of average daily gains was 0.733 to 1.018, 0.994 to 1.255, 0.947 to 1.259 and 0.736 to 0.824kg for the growing, the early-fattening, the mid- fattening and the finishing periods, respectively. The range of average daily gains for the entire period was 0.882 to 1.061kg. The gains were higher for Holstein(7.3%) and the steers(10.5%) than F1 and the heifers, respectively. Concentrates and total digestible nutrients intakes per kg gain were higher for Holstein and the heifers than F1 and the steers, respectively. These findings may indicate that feed utilization is higher for Holstein than F1, and higher for the steers than the heifers. In carcass characteristics, back fat thickness was thicker for Holstein than F1, and rib-eye area was smaller for Holstein than F1. The rib-eye area per kg carcass weight was larger for F1 and the heifers than Holstein and the steers, respectively. Meat color was better for Holstein than F1, but the sex distinction did not show any differences. In physicochemical properties of longissimus dorsi, shear force, cooking loss, water holding capacity and the panel test scores of juiciness, tenderness and flavor for F1 and the heifers were better than those for Holstein and the steers, respectively. According to the above results, we may conclude that F1 and heifers rather than Holstein and steers are recommended for high quality meat production. In steers and heifers of Holstein and F1, the optimal feeding levels may be 1.9% of apparent body weight for concentrates and 25% of concentrates intake for rice straw.

• Journal of Animal Science and Technology
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• v.53 no.2
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• pp.171-176
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• 2011

Two trials at different body weights of Hanwoo heifers (average body weight of 143 and 257 kg, respectively) were conducted to determine crude protein requirements for maintenance (CPm). Six Hanwoo heifers in each trial were used in two 3 ${\times}$ 3 Latin square design with three diets containing three levels of CP, 14 days in each period. In trial 1, the diets were based on 2.8 kg fresh wt./day/heifer timothy hay (LCP) with supplements of either 250 g ground corn and 150 g corn gluten meal (MCP) or 500 g ground corn and 300 g corn gluten meal (HCP). In trial 2, the diets were based on 4.8 kg fresh wt./day/heifer timothy hay (LCP) with supplements of either 350 g ground corn and 250 g corn gluten meal (MCP) or 700 g ground corn and 500 g corn gluten meal (HCP). In trial 1, CP intakes were 236.6, 340.1, and 459.8 g/d for LCP, MCP, and HCP, respectively. Crude protein balances were 0.51, 1.87 and 3.20g/$BW^{0.75}$/d for LCP, MCP, and HCP, respectively. In trial 2, CP intakes were 415.2, 606.9 and 793.0g/d for LCP, MCP and HCP, respectively. Crude protein balances were 0.67, 1.03, 2.99 g/$BW^{0.75}$/d for LCP, MCP, and HCP, respectively. The maintenance requirements for CP from the regression equation between CP intake and CP balance were 4.58g/$BW^{0.75}$/d (trial 1) and 5.02 g/$BW^{0.75}$/d (trial 2) and lower than the value (5.56 g/$BW^{0.75}$/d) adopted by Korean Feeding Standards for Hanwoo (2007).

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.73-73
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• 2001

This study was to examine whether the vitrified, one-step diluted and direct transferred Hanwoo IVM/IVF/IVC blastocysts can be successfully survived in vivo and they were succeeded into the live birth. For vitrification, blastocysts were serially exposed in glycerol (G) or/and ethylene glycol (EG) mixtures [10% (v/v) G for 5 min, 10% G plus 20% EG (v/v) for 5 min, and 25% G plus 25% EG (v/v) for 30 sect] which is diluted in 10% FBS added D-PBS. Thawing of straw was carried out in air for 10 sec and then in water bath of $25^{\circ}C$ for 20 sec. One-step dilution within the straw was done in water bath of $25^{\circ}C$ for 1 min. Vitrified and one-step diluted embryos were directly transferred into 36 (natural or hormone induced synchronized) recipient cows in 6 areas of Kyungsang Buk-Do. Pregnancies were confirmed at first when recipient cows did not return to the subsequent estrus cycle, and later by manual palpation per rectum on day 45, 90 and then living calves were derived into parturition. Overall pregnancy was 33.3%(12/36), However, higher pregnancy was obtained when the recipients exhibited estrus one day earlier than the age of transferred embryos (53.3 vs 25.0-27.3%), irrespective of synchronization methods. Also, parous recipients became pregnant higher than nulliparous heifers, And, there were not different in pregnancy rates by the aspect of corpus luteum (CL) quality of recipients (good, 29.4; fair, 37.5; poor, 33.3%). One hundred eight of frozen-thawed Hanwoo blastocysts were directly transferred into 36 recipient cows. In 12 of pregnant cows, 3 cows were aborted and 9 cows were calved [single, 66.7% (6/9): twin, 33.3% (3/9)]. Total embryo implantation rate was 11.1% (12/108). However, 9 Hanwoo calves were lived. Therefore, these results demonstrate that direct transfer technique of vitrified and one-step diluted bovine blastocysts can be applied easily and effectively with the higher pregnancy rate on field trial without the equipment and embryological skills.

• Journal of Animal Science and Technology
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• v.66 no.5
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• pp.920-935
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• 2024

Embryo transfer plays a crucial role in enhancing the breeding value of livestock; it has been applied in Hanwoo cattle, which is a popular breed for beef production in Korea. Both in vivo-derived (IVD) and in vitro-produced (IVP) embryos are used for this purpose; however, IVP embryos have been preferred recently owing to advancements in ovum pick-up (OPU) technology and genomic selection. Despite technological advancements, comprehensive data on large-scale OPU/IVEP/embryo transfer in Hanwoo cows are lacking. In this study, 16 elite Hanwoo donor cows were selected on the basis of specific criteria. Oocytes were retrieved from 241 cows using OPU. The collected cumulus-oocyte complexes (COCs) were matured, fertilized, and cultured in vitro to produce transferable embryos. Embryos were classified according to their developmental stage and then transferred to 675 recipient cows. A total of 3,317 COCs were collected, with an average of 13.76 COCs per cow. The number of transferable embryos produced per cow was 3.7. Hanwoo OPU-derived IVP embryos exhibited a higher production yield than the global average, indicating a stable IVEP environment. Both fresh and frozen IVP embryos yielded similar conception rates; hence, the use of vitrified-thawed embryos in transfer plans feasible. However, frozen-thawed embryos at Stage 7 had a lower conception rate than those at earlier stages. There was no significant difference between the conception rates of sexually mature heifers and postpartum cows used as recipients. The male-to-female offspring ratio increased as the developmental stage progressed. Seasonal effects on conception rates were not observed; however, higher abortion rates and a higher proportion of male offspring were observed during winter. This study provides valuable data for the Korean embryo transfer industry, enabling more strategic growth of the domestic Hanwoo embryo industry.