• 농업과학연구
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• 제45권3호
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• pp.493-498
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• 2018

There has been widespread warming and a general increase in summer temperatures over the Korean peninsula ($0.5^{\circ}C$/10 years from 2001 to 2010). South Korea is transforming into a subtropical region, and the productivity of livestock is affected by the climatic changes. In this study, we investigated whether the summer heat waves affect the developmental competency of Korean native cattle (Hanwoo), a taurine type of cattle with a small portion of indicine varieties. We collected oocytes during the summer (heat stress, HS) and autumn (non-HS condition) and examined the developmental competencies including in vitro maturation and preimplantation embryo development. No significant differences were observed between the HS and non-HS oocytes in nuclear maturation (extrusion of the polar body); however, the cleavage and blastocyst rates were significantly lower in the HS group than those in the non-HS group. The lower developmental competence of the HS oocytes compared to the non-HS is, in part, due to insufficient cytoplasmic maturation because of a higher production of Reactive oxygen species (ROS) levels as well as peri/cortical distributed mitochondria in the HS oocytes after in vitro maturation. Next, we examined the ROS and mitochondria distribution and found a significant increase in the levels of ROS in the HS oocytes and a polarized distribution (pericortical cytoplasm) of mitochondria in the HS oocytes. In summary, impaired cytoplasmic maturation of oocytes from exposure to HS affects the preimplantation embryo development by dysfunction of mitochondria. To improve reproductive performance, embryo transfer using cryopreserved embryos/oocytes is recommended in the hot summer season of South Korea.

• 한국임상수의학회지
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• 제24권3호
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• pp.453-456
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• 2007

This report described an outbreak of blindness caused by hypovitaminosis A in Hanwoo (Korean native cattle) in Gyeongsangbukdo province, Korea. The diagnosis was based on clinical findings, analysis of diet, and concentration of vitamin A and carotene in serum and/or feedstuff. Thirty eight of 48 cows were found to be affected. The causative diet contained higher levels of crude protein, net energy and crude fat and lower level of total fiber and crude fiber. Surprisingly, vitamin A was not detected in the causative diet. Treatment of vitamin A to Hanwoo that had blindness did not induce further progress of the symptom. Furthermore, there were no additional diseases detected. Based on the observations described above, this case was diagnosed as hypovitiminosis A.

• Journal of Animal Science and Technology
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• 제48권4호
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• pp.595-602
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• 2006

본 연구는 우리나라 재래종인 한우로부터 초유를 얻어 Lf을 분리정제한 후 한우 Lf와 젖소 Lf의 항균활성을 확인하였다. E. coli O111및 기타 미생물에 대한 항균성은 젖소 Lf가 한우 Lf 보다 높았으며, 젖소 Lf 가수분해물도 한우 Lf 가수분해물보다 마찬가지로 높았다. MIC에서는 E. coli O111 경우 젖소 Lf가 1.5mg/ml, 한우 Lf은 2.75mg/ml이며 젖소 Lf 가수분해물은 0.12mg/ml, 한우 Lf 가수분해물은 0.25mg/ml로 항균성 실험과 동일하게 젖소 Lf 가수분해물의 항균활성이 더 높은 것으로 나타났다. 한편 Lf과 lysozyme의 첨가는 항균활성을 상승시키는 효과를 나타내었다.

• 농업과학연구
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• 제47권3호
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• pp.667-672
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• 2020

It is well known that intensive selection caused a decline in reproductive performance in dairy cattle. Interestingly, the reproductive performances including fertility and calving interval of Korean native beef cattle have declined in the last 20 years, suggesting that a breeding program focusing on carcass weight and intramuscular fat may affect the reproductive physiology in Korean native beef cattle, too. In this study, we analyzed the calving interval (CI) and selection index (SI) based on genome-wide association studies (GWAS) of Hanwoo cows for seven years (2013 - 2019). Multiparous cows (4.5 ± 0.11) were analyzed, which were bred by artificial insemination (AI). We first examined the distribution of the AIs and calving dates. About 40% of the AIs were carried out in May to June and October to December; subsequently, calving was observed from March to April and August to October, respectively, indicating the cows were seasonally bred. No correlation between CI and SI was found (y = 0.0459x - 17.64; R² = 0.0356), but the ratio of cows with a positive SI was higher in the longer CI group compared to the shorter group, suggesting that the selection for meat quality and quantity may affect the reproductive performances. In addition, the average value of SI was - 3.42 in the CI < 400 while + 5.79 in the CI > 400 although the values were not statistically significant. However, our results suggest that reproductive indices such as fertility and CI should be considered for sustainability in the Hanwoo breeding selection program.

• Journal of Animal Science and Technology
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• 제64권5호
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• pp.897-910
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• 2022

Bovine fecal microbiota is important for host health and its composition can be affected by various factors, such as diet, age, species, breed, regions, and environments. The objective of this study was to evaluate the impact of diet and gender on fecal microbiota in Korean native Hanwoo cattle. The 16S rRNA gene amplicon sequencing of fecal microbiota was conducted from 44 Hanwoo cattle divided into four groups: (1) 11 heifers fed an oat hay plus total mixed ration (TMR) diet for breeding (HOTB), (2) 11 heifers fed an early fattening TMR diet (HEFT), (3) 11 steers fed the early fattening TMR diet (SEFT), and (4) 11 steers fed the late fattening TMR diet (SLFT). Firmicutes and Bacteroidota were the first and second most dominant phyla in all the samples, respectively. The Firmicutes/Bacteroidota (F/B) ratio associated with feed efficiency was significantly greater in the SLFT group than in the other groups. At the genus level, Romboutsia, Paeniclostridium, and Turicibacter were the most abundant in the SLFT while Akkermansia, Bacteroides, and Monoglobus were the most abundant in the HOTB group. Although the same early fattening TMR diet was fed to Hanwoo heifers and steers, Marvinbryantia and Coprococcus were the most abundant in the HEFT group while Alistipes and Ruminococcus were the most abundant in the SEFT group. Shannon and Simpson diversity indices were significantly lower in the SLFT group than in the other groups. Distribution of fecal microbiota and functional genetic profiles were significantly different among the four treatment groups. The present study demonstrates that different diets and genders can affect fecal microbiota and the F/B ratio may be associated with feed efficiency in Hanwoo cattle. Our results may help develop strategies to improve gut health and productivity through manipulation of fecal microbiota using the appropriate diet considering Hanwoo cattle gender.

• Reproductive and Developmental Biology
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• 제31권1호
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• pp.43-48
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• 2007

본 연구는 인공수정 기법을 이용한 칡소의 증식효율을 검토하고자 칡소 종모우의 정액을 채취하여 종모우별 정액성상, 동결융해 후 정액의 특성, 수태율 평가를 위한 체외수정 및 인공수정 후 수태율과 송아지의 모색 분포 등에 대하여 검토하였다. 정액은 호반모를 가진 수컷 6두에서 채취하였으며, 동결 융해 후 체외수정을 실시하였다. 총 18두의 칡소 및 일반 한우 암컷에 인공수정 후 수태율을 확인하였고, 생산된 40두의 송아지를 대상으로 모색을 분석하였다. 칡소 정액의 동결 전 일반 성상은 개체 간에 차이가 없었으며, 동결 후의 생존율과 활력에서도 개체별 차이가 없었다. 체외수정에 의한 수정 능 분석 결과, 수정율에는 차이가 없었으나 배반포 발육율이 일반 한우에 비하여 칡소 정액 체외수정 시 25.9%로 유의하게 높았다(p<0.05). 인공수정 후 임신율에는 일반 한우와 칡소 간에 차이가 없었다. 칡소 정액의 인공수정 후 태어난 송아지의 모색 표현형은 40두의 송아지 중 호반모(Tiger)가 17두(42.5%)로, 황흑모, 흑황모, 흑모 및 황모에 비하여 높았으나 전체적으로 낮은 발현율을 나타내었다. 또한 호반모 암컷에 인공수정한 경우에도 55%의 송아지만 호반모로 발현되었다. 이상의 결과는 인공수정에 의한 칡소의 증식이 가능하나 호반모 칡소의 발현 빈도를 높이기 위한 연구가 필요할 것으로 사료된다.

• 현장농수산연구지
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• 제17권1호
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• pp.3-20
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• 2015

Vitamin A exerts a broad range of effects on many essential life processes. But, since vitamin A is known to negatively affect the development of adipocytes, extensive research has been conducted to improve marbling score in beef cattle by feeding vitamin A-deficient diets. In Japan, the method of fattening Wagyu cattle using vitamin A-deficient diets has been widely adapted. Recently, the method of feeding vitamin A-deficient diets in Korean native cattle (Hanwoo) has been spread by feed companies and TMR plants. But proper guidelines in feeding vitamin A-deficient diets should be provided, otherwise it can adversely affect the health of cattle. To maximize marbling score, a controlled level of vitamin A in blood needs to be maintained and the proper period for feeding vitamin A-deficient diets should be adapted. This review was conducted to highlight the regulatory effects of vitamins A on adipocyte differentiation, and offer a potential guideline for improving beef quality grades in Hanwoo.

• 한국축산식품학회지
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• 제34권6호
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• pp.763-768
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• 2014

The identity of 45 Hanwo and 47 imported beef (non-Hanwoo) samples from USA and Australia were verified using the microsatellite (MS) marker and single nucleotide polymorphism (SNP) methods. Samples were collected from 19 supermarkets located in the city of Seoul and Gyeonggi province, South Korea, from 2009 to 2011. As a result, we obtained a 100% concordance rate between the MS and SNP methods for identifying Hanwoo and non-Hanwoo beef. The MS method presented a 95% higher individual discriminating value for Hanwoo (97.8%) than for non-Hanwoo (61.7%) beef. For further comparison of the MS and SNP methods, blood samples were collected and tested from 54 Hanwoo ${\times}$ Holstein crossbred cattle (first, second, and third generations). By using the SNP and MS methods, we correctly identified all of the first-generation crossbred cattle as non-Hanwoo; in addition, among the second and third generation crossbreds, the ratio identified as Hanwoo was 20% and 10%, respectively. The MS method used in our study provides more information, but requires sophisticated techniques during each experimental process. By contrast, the SNP method is simple and has a lower error rate. Our results suggest that the MS and SNP methods are useful for discriminating Hanwoo from non-Hanwoo breeds.

• 한국축산식품학회지
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• 제25권2호
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• pp.203-209
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• 2005

유전자수준의 염기서열에 근거를 둔 유전자 감식기법을 활용하여 개체간의 유전적 차이로 한우육과 젖소육 혹은 수입육의 구별방법을 개발하기 위한 연구가 많이 수행되었다. 그 중 real-time PCR 판별방법은 기존 PCR의 단점인 허위양성을 배제시켜 그 결과의 신뢰성이 높으며, PCR 산물들의 제한효소에 의한 절단 및 겔에서의 확인 등의 과정을 생략시킬 수 있어 짧은 시간 내에 다량의 시료를 분석할 수 있고 민감도가 높아 쇠고기가 포함된 가공식품의 분석도 가능하다는 장점이 있다. 본 연구는 시중에서 한우로 유통되는 쇠고기(생육 또는 양념육)의 DNA를 추출하여 real-time PCR을 통해서 모색유전자의 유전자 형(C-type, C/T-type or T-type)으로 한우육과 젖소육 및 수입육을 구분하였다. 한우육만을 판매한다는 시중 음식점 41개소에서 쇠고기(생육 또는 양념육)를 수거하여 분석한 결과, 분석된 41개의 시료 중 29개가 한우 유전자형으로, 12개의 시료가 젖소 또는 수입육 유전자형으로 판별되었다. 따라서 분석된 시료들의 한우육(T-type) 비율은 $70.1\%$, 그리고 젖소육 또는 수입육 비율은 $29.3\%$(C/T-type; $12.2\%$, C-type; $17.1\%$)이었다.

• 한국수정란이식학회지
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• 제30권3호
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• pp.189-193
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• 2015

Calculating break-even price of calf production is closely associated with reproductive efficiency. To determine the price, we need data from reproduction records including number of claves weaned, number of cows exposed for breeding, and annual cash coast per cow, and average weaning or market weight of claves sold and retained. Unfortunately, the data were not available in Korea native cow (Hanwoo). To evaluate the performance and the price, we collected calving interval from about 60,000 cows for last 10 years and estimated reproductive performance. Calving interval was increased 4.3% and pregnancy rate was decreased about 1.4~2.8% year-on-year. Increases in growth rates of number of cow and semen per calf supported the low reproductive performance. Finally, break-even price was calculated using estimated percent calf crop and demonstrated that growth rate of break-even price is larger than that of annual cash per cow, suggesting cow-calf profitability and financial efficiency in Korea native cow (Hanwoo) is getting worse.