• 농업과학연구
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• 제45권1호
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• pp.74-83
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• 2018

Four early-fattening Hanwoo steers weighing $247{\pm}13.5kg$ were used within a $4{\times}4$ Latin square design to establish a nutrient requirement for maintenance and to investigate nutritional changes in the steers under heat stress condition. The steers were fed four different energy level diets: 100% (control) and 100%, 115% and 130% of total digestible nutrients (TDN) requirement of the early-fattening Hanwoo steers for maintenance based on the Korean Feeding Standard for Hanwoo. The steers in the control were housed with no stress (temperature $24^{\circ}C$ and humidity 60%), whereas the steers in the other groups were under heat stress (temperature $30^{\circ}C$ and humidity 70%). True digestibilities of dry matter (DM) and other nutrients were not significantly (p > 0.05) affected by heat stress (i.e., control vs T100). This may be the result of a lower DM intake than that of the Korean feeding standard due to the establishment of the nutrients requirement under heat stress. Heat stress and different energy intake levels did not affect the blood metabolite concentrations. Average daily gain (ADG) for T100 (-69.6 g) was lower than that of the control (-44.6 g, numerically), T115 (44.6 g, p < 0.05) and T130 (83.3 g, p < 0.05), respectively. Based on the ADG and TDN intake, the equation (Y = 0.1814X + 111.5) for the TDN requirement of the early fattening Hanwoo steers for maintenance was calculated, indicating that 11.5% of TDN requirement for maintenance under heat stress may be additionally supplied.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2017년도 춘계공동학술대회
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• pp.23-23
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• 2017

Recent favor on high quality food and concern on food safety have demonstrated the superiority of Hanwoo (Korean native cattle). In general, the price of cow is higher than those of steer and bull, causing cheating issues in the market. Hence, this study is to discriminate genders of Hanwoo with identification of factors which highly influence gender discrimination based on the big-size deboning data. Totally, there were 31 variables in the deboning data, and we divided into them two categories: data obtained before and after deboning. Discriminant function analysis was then applied into the data to determined the accuracy of gender discrimination in Hanwoo. The result showed that Hanwoo could be classified by gender with 99.2% of accuracy when using all 31 variables. In detail, it was possible to identify 93 of 94 bulls (98.9%), 96 of 96 cows (100%) and 74 of 75 steers (98.7%). The most significant variables was chuck, sirloin, armbone shin, plates, retail and cuts percentage, sequentially. With variables obtainable before deboning, accuracies of classification were 91.5% for bulls, 92.7% for cows, and 89.3% for steers. The most significant variables was water, cold carcass weight and back-fat thickness. The discrimination accuracy was higher with data obtainable after deboning: bulls (98.9%), cows (99.0%) and steers (98.7%). In this case, chuck, sirloin and armbone shin were the factors determined the classification ability. This study showed that Hanwoo can be classified based on deboning data with appropriate statistics, further suggesting weight of cut of beef might be the standard for gender classification.

• Journal of Animal Science and Technology
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• 제55권5호
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• pp.405-416
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• 2013

본 연구는 도체월령별 도체형질의 변화를 분석하여 적정 도축시기를 결정하는 데 필요한 정보를 얻기 위한 목적으로 실시하였으며, 2005년 10월부터 2011년 9월 사이에 도축된 거세우 17,249두의 도체형질자료를 이용하였다. 각 도체형질의 평균과 표준편차는 도축일령, 도체중, 등지방두께, 등심면적, 근내지방도, 육량지수, 도체단가 및 도체 총가격에서 각각 $940.4{\pm}73.00$, $437.0{\pm}48.70$ kg, $12.1{\pm}4.32$ mm, $90.3{\pm}9.51cm^2$, $5.7{\pm}1.86$, $65.13{\pm}3.23$, $14.150{\pm}1.77$천원 및 $6181.18{\pm}1009.46$천 원으로 나타났다. 도체월령별 회귀계수에서 조기 도축그룹에서는 도체 단가를 제외한 전체 형질들에서, 만기 도축그룹에서는 근내지방도를 제외한 전체 형질들에서 월령별 회귀계수가 유의성이 인정되었다. 수익을 얻기 위해서는 28개월령 이전으로 도축시기를 결정해야 할 것으로 판단된다.

• Asian-Australasian Journal of Animal Sciences
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• 제27권9호
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• pp.1250-1253
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• 2014

The objective of this study was to estimate the parameters of Gompertz growth curves with the measurements of body conformation, real-time ultrasound longissimus dorsi muscle area (LMA) and backfat thickness (BFT) in Hanwoo cows. The Hanwoo cows (n = 3,373) were born in 97 Hanwoo commercial farms in the 17 cities or counties of Gyeongbuk province, Korea, between 2000 and 2007. A total of 5,504 ultrasound measurements were collected for the cows at the age of 13 to 165 months in 2007 and 2008. Wither height (HW), rump height (HR), the horizontal distance between the top of the hips (WH), and girth of chest (GC) were also measured. Analysis of variance was conducted to investigate variables affecting LMA and BFT. The effect of farm nested in location was included in the statistical model, as well as the effects of HW, HR, WH, and GC as covariates. All of the effects were significant in the analysis of variance for LMA and BFT (p<0.01), except for the HR effect for LMA. The two ultrasound measures and the four body conformation traits were fitted to a Gompertz growth curve function to estimate parameters. Upper asymptotic weights were estimated as $54.0cm^2$, 7.67 mm, 125.6 cm, 126.4 cm, 29.3 cm, and 184.1 cm, for LMA, BFT, HW, HR, WH, and GC, respectively. Results of ultrasound measurements showed that Hanwoo cows had smaller LMA and greater BFT than other western cattle breeds, suggesting that care must be taken to select for thick BFT rather than an increase of only beef yield. More ultrasound records per cow are needed to get accurate estimates of growth curve, which, thus, helps producers select animals with high accuracy.

• Asian-Australasian Journal of Animal Sciences
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• 제27권9호
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• pp.1219-1227
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• 2014

A whole genome association (WGA) study was carried out to find quantitative trait loci (QTL) for sensory evaluation traits in Hanwoo. Carcass samples of 250 Hanwoo steers were collected from National Agricultural Cooperative Livestock Research Institute, Ansung, Gyeonggi province, Korea, between 2011 and 2012 and genotyped with the Affymetrix Bovine Axiom Array 640K single nucleotide polymorphism (SNP) chip. Among the SNPs in the chip, a total of 322,160 SNPs were chosen after quality control tests. After adjusting for the effects of age, slaughter-year-season, and polygenic effects using genome relationship matrix, the corrected phenotypes for the sensory evaluation measurements were regressed on each SNP using a simple linear regression additive based model. A total of 1,631 SNPs were detected for color, aroma, tenderness, juiciness and palatability at 0.1% comparison-wise level. Among the significant SNPs, the best set of 52 SNP markers were chosen using a forward regression procedure at 0.05 level, among which the sets of 8, 14, 11, 10, and 9 SNPs were determined for the respectively sensory evaluation traits. The sets of significant SNPs explained 18% to 31% of phenotypic variance. Three SNPs were pleiotropic, i.e. AX-26703353 and AX-26742891 that were located at 101 and 110 Mb of BTA6, respectively, influencing tenderness, juiciness and palatability, while AX-18624743 at 3 Mb of BTA10 affected tenderness and palatability. Our results suggest that some QTL for sensory measures are segregating in a Hanwoo steer population. Additional WGA studies on fatty acid and nutritional components as well as the sensory panels are in process to characterize genetic architecture of meat quality and palatability in Hanwoo.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2001년도 춘계학술발표대회
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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.

• Asian-Australasian Journal of Animal Sciences
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• 제25권7호
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• pp.1029-1037
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• 2012

The present study was designed to investigate the effect of ${\alpha}$-melanocyte-stimulating hormone (${\alpha}$-MSH), nitric oxide (NO) and L-cysteine on melanin production and expression of related genes MC1R, Tyr, Tyrp-1 and Tyrp-2 in muzzle melanocytes of differently colored three native Hanwoo cattle. Muzzle samples were taken from black, brindle and brown Hanwoo and purified melanocytes were cultured with ${\alpha}$-MSH, nitric oxide and L-cysteine at 100 nM, $50{\mu}M$ and 0.07 mg/ml of media respectively. The amounts of total melanin, eumelanin and mRNA expression at Tyr, Tyrp-1, Tyrp-2 and MC1R levels were quantified. ${\alpha}$-MSH and nitric oxide significantly increased (p<0.05) the amount of total melanin in black and brindle whereas eumelanin production in brown Hanwoo muzzle melanocytes. On the contrary, L-cysteine greatly (p<0.05) depressed the eumelanin production in black color but increased in brown. Simultaneously, up regulation of Tyr by nitric oxide and ${\alpha}$-MSH and down regulation of Tyr, Tyrp-2 and MC1R genes by L-cysteine were observed in muzzle melanocytes of all three phenotypes. The results of this study revealed nitric oxide and ${\alpha}$-MSH contribute hyper-pigmentation by enhancing eumelanogenesis whereas L-cysteine contributes to pheomelanin production in different colored Hanwoo muzzle melanocytes.

• 한국환경과학회지
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• 제22권9호
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• pp.1235-1239
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• 2013

The effects of probiotic additions to feed and manure on temperature, humidity and carbon dioxide ($CO_2$) emissions in Hanwoo manure during summer (4 weeks) were evaluated. Fifteen Hanwoo (24-mo-old, $580{\pm}20kg$) were housed in individual pens ($5{\times}8m$) and randomly assigned to 1 of 3 treatments (n = 5 cattle per treatment). Hanwoo were fed experimental rations as follows: control (10 kg roughage + 2 kg concentrate); T1 (10 kg roughage + 2 kg concentrate, 2% probiotics on as-fed basis); and T2 (10 kg roughage + 2 kg concentrate, 2% probiotics on as-fed basis + 7 kg probiotics as top-dressing on the surface of Hanwoo manure). In comparison to the control, the addition of probiotics to feed or feed and manure had an effect (P < 0.05) on temperature and humidity over the 4 weeks, except for humidity at 0 weeks. The only significant difference (P < 0.05) observed in $CO_2$ emission was among all treatments at 3 and 4 weeks (but not at 0 through 2 weeks). These results indicated that use of probiotics as feed and manure additives did not have a significant effect on environmental parameters.

• Journal of the Korean Data and Information Science Society
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• 제27권3호
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• pp.741-747
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• 2016

본 연구에서는 국가단위 개체모형을 이용하여 일반농가 한우의 도체중, 등심단면적, 등지방두께, 국내지방도에 대한 유전력를 추정하고 이를 국가단위 종모우 선발용 후대검정우 집단의 유전력과 비교하여 일반 한우농가 개량방향에 효율적인 기초자료로 활용하고자 한다. 일반농가 한우 107,020두 중 생산정보와 2008년부터 2012년까지의 도체성적 기록이 정확한 일반농가 한우 5,843두를 대상으로 다형질 개체모형을 사용하여 유전력를 추정하였다. 유전력를 추정하기 위해 도체형질에는 출생년도, 사육지역을 고정효과, 사육일령을 공변량으로 포함하였다. 일반농가 한우의 유전력를 추정한 결과 도체형질에 대한 유전력은 도체중 0.19, 등심단면적 0.17, 등지방두께 0.20, 근내지방도 0.23 이며 국가단위 씨수소 선발용 후대검정우 집단의 유전력에 비해 낮았다. 이는 사육지역의 환경, 암소 유전능력과 사육개월의 차이로 인해 낮게 나타났다. 따라서 본 연구에서도 현재 실시되어지고 있는 국가단위 씨수소 선발용 개체모형에 농가 한우집단에 사용할 수 있는 유전요인을 포함시켜 실용화 개체모형 개발이 시급하다.

• 한국환경과학회지
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• 제21권5호
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• pp.647-654
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• 2012

The goal of this study was to investigate the distribution chart of management and satisfaction through Hanwoo education program and to provide fundamental data and development conformity available on the management and educational program to managers. In this study, we chose 75 managers taking part in Hanwoo education program as pre-test and applied satisfaction for education program to 33 managers randomly selected as post-test. The results of this study are as follows: First, age and academic career had a significant (P<0.05) effect on breeding size, breeding career, sales, and management methods. This may be due to the fact that managers in Hanwoo industry tended to raise academic standards and the age group moved towards young age rather than middle and old ages. However, an academic career was unaffected by sale and management methods. Second, managers who randomly selected the education program showed higher satisfaction about the program and lower or usual interest and intention in the educational environment, incidental facilities, and reviews. In conclusion, to equip the constituent parts of education program with entire propriety and an effective running system, information on breeding size and breeding career for managers in Hanwoo Industry with respect to age and academic career had to be clearly premeditated. It also needed the educational program to look at it from the standpoint of the managers.