• Korean Journal of Veterinary Research
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• v.45 no.3
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• pp.335-339
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• 2005

The melanocortin 1 receptor (MC1R) plays an important role in regulation of melanin pigment synthesis within mammalian melanocytes. Mutations within the gene encoding MC1R have been shown to explain coat color variations within several mammalian species including cattle. To develope a rapid and accurate method for the identification of Hanwoo, we performed a modified PCR-RFLP analysis of MC1R gene using single nucleotide polymorphism (SNP) within MC1R as a target. A size of 538 bp (537 bp for Hanwoo) was amplified by PCR, digested with Hpa II, and electrophoresed on a 1.5% agarose gel. A PCR product from Hanwoo showed a single band of 537 bp, whereas two fragments of 328 bp and 210 bp were detected in both Holstein and Black angus. The current result suggests that the PCR-RFLP using our primers and enzyme digestion system would be very accurate, easy and reproducible method to discriminate between Hanwoo and Holstein/Black angus meat.

• Journal of agriculture & life science
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• v.45 no.2
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• pp.85-92
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• 2011

The current study was conducted to investigate effects of sera taken from Hanwoo at different age on adipocyte differentiation. Sera were taken from Korean native (Hanwoo) steers at 6, 12, 18, and 24 months of age, respectively and supplemented to 3T3-L1 preadipocytes after the cells reached confluence and maintained 10 days thereafter. For the first 2 days (48 h), cells were induced to differentiate by addition of differentiation factors, methylisobutylxanthine, daxamethasone, and insulin. After the differentiation, the cells were incubated without differentiation factors except insulin. The cells lost their fibroblastic shape and showed round-up appearances after 10 days incubation with FBS and the sera of Hanwoo steers. Big lipid droplets appeared in the cells cultured with FBS and the sera taken from Hanwoo at 18 and 24 months of age. After 18 months of age, GPDH activity was statistically higher than 6 and/or 12 months of age (P < 0.05). Based on morphology and Sn-glycerol-3-phosphate dehydrogenase activities, Hanwoo steers expressed aged-dependent adipogenic activities, indicating that aged sera may result in high adipocyte differentiation. It is concluded that the 18 months of age may be 'threshold' to express major adipogenic activities. This may strongly support previous field studies reporting considerable increase in fat contents of Hanwoo carcass at over 18 months of age.

• Journal of Embryo Transfer
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• v.33 no.4
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• pp.321-326
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• 2018

In this study, two epididymal spermatozoa recovery methods in relation to sperm number, motility, viability and acrosome reaction were examined. Seven bulls were castrated and 7 testicles with epididymides were transferred to the laboratoy. Epididymis in each bull was randomly used for flushing and mincing methods with semen extender (Optixcell, IMV, France). The recovered spermatozoa with adjusted sperm concentration to $40{\times}10^6cells/mL$ was diluted with optixcell and cryopreserved. In experiment 1, the difference in the total number of spermatozoa using flushing and mincing methods was insignificant (2570.0 and $2505.2{\times}10^6cells/mL$, respectively). For experiment 2, the percentage of motile spermatozoa and motility parameters between flushing and mincing methods were studied through the use of sperm class analyzer after frozen-thawing. The percentage of total motile sperm between flushing and mincing methods was almost the same with $89.5{\pm}12.8$ and $91.4{\pm}7.9%$, respectively. The same is the case with experiment 3 wherein the viability and acrosomal integrity of frozen-thawed epididymal spermatozoa by flushing and mincing was insignificantly different. The results from the study showed that both flushing and mincing methods can be used for epididymal spermatozoa recovery in bull.

• Korean Journal of Agricultural Science
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• v.48 no.3
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• pp.527-534
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• 2021

This study investigated the possibility of performing selection using 30-month carcass traits by estimating the genetic parameters of 24- and 30-month carcass traits. Data used in this study were the carcass traits of 13,151 heads slaughter at the age of 24 and 30 months. As a result of the study, the heritability of backfat thickness, carcass weight, eye muscle area and marbling score at 24 months of age were estimated to be 0.588, 0.354, 0.467 and 0.587, respectively. The heritability of backfat thickness, carcass weight, eye muscle area and marbling score at 30 months of age were estimated to be 0.498, 0.577, 0.505 and 0.530, respectively. The ranking correlation was 0.516 between the carcass selection indices of 24 and 30 months of age. By providing a 30-month selection index, it is possible to use semen suitable for farm profits, and more semen information can be provided to farms than previously. Furthermore, studies on a selection index based on 30-month carcass traits are needed to provide highly accurate information.

• Reproductive and Developmental Biology
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• v.37 no.3
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• pp.123-127
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• 2013

The objective of this study was to compare the effects of the levels of inbreeding on body weight traits between two breed populations, Hanwoo and Korea Brindle cattle. Birth weight (BW), weaning weight (WW), body weight at 6 months of age (W6) and yearling weight (YW). Records of 1,745 calves (1,513 from Hanwoo, and 232 from Korea Brindle calves) were collected from Livestock Research Institutes in Kangwon, Gyeongbuk and Chungbuk provinces. The least squares means (LSM) and their standard errors for BW, WW, W6 and YW were $25.4{\pm}0.1$ kg, $81.0{\pm}1.8$ kg, $146.1{\pm}3.7$ kg and $291.5{\pm}2.4$ kg, respectively in Hanwoo calves and $22.6{\pm}0.3$ kg, $79.9{\pm}2.3$ kg, $137.6{\pm}4.6$ kg and $249.3{\pm}6.6$ kg, respectively in Korea Brindle calves. Pedigree data showed that 14.8% (316 out of 2131) of Hanwoo was inbred and the average inbreeding coefficient was 0.0209 (2.09%). Inbreeding coefficients of ten calves out of 316 total inbred Hanwoo calves were 12.5% or higher, whereas those of the other 306 calves were less than 12.5%. In both breeds, calves were divided into three groups of inbreeding classes - highly inbred group($F{\geq}0.125$), lowly to medially inbred group(0

• Reproductive and Developmental Biology
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• v.34 no.3
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• pp.263-270
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• 2010

Luteal cells produce progesterone that supports pregnancy. Steroidogenesis requires coordination of the anabolic and catabolic pathways of lipid metabolism. In the present study, the corpus luteum (CL) in early pregnancy established from luteal phase and pregnant phase was analyzed. The first study determined progesterone changes in the bovine CL at day 19 (early maternal recognition period) and day 90 in mid-pregnancy and compared them to the CL from day 12 of the estrous cycle. CL alternation was tested using two-dimensional polyacrylamide gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF). Comparing CL from luteal phase to those from pregnant phase counterparts, significant changes in expression level were found in 23 proteins. Of these proteins 17 were not expressed in pregnant phase CL but expressed in luteal phase counterpart, whereas, the expression of the other 6 proteins was limited only in pregnant phase CL. Among these proteins, vimentin is considered to be involved in regulation of post-implantation development. In particular, vimentin may be used as marker for CL development during pregnancy because the expression level changed considerably in pregnant phase CL tissue compared with its luteal phase counterpart. Data from 2-DE suggest that protein expression was disorientated in mid pregnancy from luteal phase, but these changes was regulated with progression of pregnancy. These findings demonstrate CL development during mid-pregnancy from luteal phase and suggest that alternations of specific CL protein expression may be involved in maintenance of pregnancy.

• Korean Journal of Agricultural Science
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• v.42 no.4
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• pp.361-368
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• 2015

This study was to investigate the effect of high energy diet on characteristics of Hanwoo steers distributed by estimated breeding value (EBV). The aim of this experiment was to determine the effect of high energy diet on the high and low beef group distributed by EBV for quality grades. We hypothesized that high energy diet is able to increase quality traits in high EBV groups when fed a high energy diet. A $2{\times}2$ factorial arrangement (High energy, control vs high EBV, low EBV) in a completely random design was used to feed 26 Hanwoo steers. Blood was drawn from each steers from 11 to 28 months. ADG and feed efficiency were not different between high energy and control diet (P>0.05). The level of DMI was greater at calf and early fattening diet in low EBV groups (P<0.05). Serum glucose and tryglyceride conecntrations were increased (P<0.05) by high EBV group from 22 to 28 month old. Serum NEFA concentration were plateau at 24 months at high EBV group and steady reduced by high energy diet (P<0.05). This data indicated that high energy diets increased serum glucose and triglyceride concentrations of high EBV steers at final fattening period.

• Journal of Animal Science and Technology
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• v.51 no.5
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• pp.387-394
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• 2009

This study was carried out to screen and identify the chitinase and chitosanase producing microorganisms from the feces of calves medicated DFM sincluding chitin in order to do the immune fortification of Korean Native calves. Ten isolates were grown in the medium containing chitin and chitosan that had more than $10^5$ cfu/g in feces. Among these 10 strains, 2 strains (HANDI 110 and HANDI 309) had the chitinase activities and 2 strains (HANWOO and HANYOO) had the chitosanase activities in calves' feces. They showed no reaction in hemolysis tests by utilizing chitin and chitosan. The results from morphological, physicochemical and genetical identification indicated the HANDI 110 as a strain of Escherichia fergusonii, HANDI 309 was identified as a strain of Acinetobacter parvus, HANWOO was identified as a strain of Comamonas koreensis, and HANYOO as a strain of Chryseobacterium indologenes.

• Journal of Practical Agriculture & Fisheries Research
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• v.24 no.2
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• pp.12-22
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• 2022

The purpose of this study is to design a farming model for Hanwoo start-up farmers. I prepared a Hanwoo production plan model according to the growth cycle of Hanwoo using EXCEL. The Hanwoo production plan model was simulated in two model: Model 1 (a model that only purchases Hanwoo calf) and Model 2 (a model that purchases both Hanwoo cow and Hanwoo calf). Next, I reviewed the profits and costs of two Hanwoo simulation models. As a result of the analysis, Model 2 has the following characteristics compared to Model 1. First, Model 2 requires a lot of initial investment. Second, Model 2 is advantageous in terms of farm cash balance because imports occur every year. Third, Model 2 can efficiently use facilities and machines.

• Journal of Biosystems Engineering
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• v.35 no.5
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• pp.350-356
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• 2010

The fans installed in standard Hanwoo loose barns (room size : 10 m (width) $\times$ 5 m (length)) are frequently used to reduce Hanwoo's heat stress during hot weather and to dry the wet floor. However, the most effective method of installing fans has not been suggested yet. Therefore, this study was carried out to evaluate two methods of installing fans under the ceiling of Hanwoo loose barn by using CFD (Computational Fluid Dynamics) code, FLUENT and to recommend the optimum fan installing method. The fan installation options were fan tilting angles of $45^{\circ}$ and $0^{\circ}$ (horizontal). The fans of 1 m diameter were installed at 3 m above floor. A velocity scale on 10 cm and 110 cm above floor and air flow pattern were used as the parameters to evaluate the fan installing methods. The fans tilted at $45^{\circ}$ angle produced higher wind at 10 cm and 110 cm above floor and more uniform air flow pattern, compared with the fans installed horizontally. Based on these results, fans tilted at $45^{\circ}$ angle may help to reduce Hanwoo's heat stress and will dry the floor better than fans installed horizontally. Therefore, it is suggested that the fans of 1 m diameter in a standard Hanwoo loose barn should be installed at a $45^{\circ}$ tilt angle and 3 m above floor with spacing of 5 m at the center of a room column.