• Korean journal of applied entomology
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• v.61 no.4
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• pp.675-688
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• 2022

Produced by steaming mature silkworms, HongJam is a natural functional food with various health-promoting effects. The current standard HongJam production protocol involves freezing and freeze-drying steamed mature silkworms for convenient long-term storage and/or selling it to customers. However, freeze-drying HongJam requires a range of processes and costs, which have contributed to its high resale value. In this study, we found that the cost of manufacturing HongJam powder could be reduced by homogenizing steamed mature silkworms using a high-speed blender and digital homogenizer, followed by spray drying. After the homogenized HongJam solution was digested by directly adding food-graded proteases, food-graded protease-digested homogenized HongJam solution was spray-dried. Food-graded digested protease or non-digested homogenized HongJam solutions could be used to produce food for special medical use for patients with general or specific diseases. This more efficient HongJam processing protocol proposed in this study can facilitate the development of sericulture farms and related industries by reducing the production costs of HongJam and its associated products.

• Journal of Animal Science and Technology
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• v.65 no.2
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• pp.324-335
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• 2023

Korea, located in East Asia in the northern hemisphere, is experiencing severe climate changes. Specifically, the heat stress caused by global warming is negatively affecting the dairy sector, including milk production and reproductive performance, as the major dairy cattle Holstein-Friesian is particularly susceptible to heat stress. Here, we collected artificial insemination and pregnancy data of the Holstein and the Jersey cows from a dairy farm from 2014 to 2021 and analyzed the association between the conception rate and the temperature-humidity index, calculated using the data from the closest official weather station. As the temperature-humidity index threshold increased, the conception rate gradually decreased. However, this decrease was steeper in the Holstein breed than in the Jersey one at a temperature-humidity index threshold of 75. To evaluate the effects of heat stress on the oocyte quality, we examined the nuclear and cytoplasmic maturation of Holstein (n = 158, obtained from six animals) and Jersey oocytes (n = 123, obtained from six animals), obtained by ovum pick-up. There were no differences in the nuclear maturation between the different conditions (heat stress: 40.5℃, non- heat stress: 37.5℃) or breeds, although the Holstein oocytes seemed to have a lower metaphase II development (p = 0.0521) after in vitro maturation under heat stress conditions. However, we found that the Holstein metaphase II oocytes exposed to heat stress presented more reactive oxygen species and a peripheral distribution of the mitochondria, compared to those of the Jersey cattle. Here, we show that weather information from local meteorological stations can be used to calculate the temperature-humidity index threshold at which heat stress influences the conception rate, and that the Jersey cows are more tolerant to heat stress in terms of their conception rate at a temperature-humidity index over 75. The lower fertility of the Holstein cows is likely attributed to impaired cytoplasmic maturation induced by heat stress. Thus, the Jersey cows can be a good breed for the sustainability of dairy farms for addressing climate changes in South Korea, as they are more resistant to hyperthermia.

• Korean Journal of Veterinary Service
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• v.45 no.1
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• pp.1-11
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• 2022

A novel porcine circovirus 4 (PCV4) was recently identified in Chinese and Korean pig herds. Although several conventional polymerase chain reaction (cPCR) and real-time PCR (qPCR) assays were used for PCV4 detection, more sensitive and reliable qPCR assay is needed that can simultaneously detect PCV4 and internal positive control (IPC) to avoid false-negative results. In the present study, a duplex qPCR (dqPCR) assay was developed using primers/probe sets targeting the PCV4 Cap gene and pig (glyceraldehyde-3-phosphate dehydrogenase) GAPDH gene as an IPC. The developed dqPCR assay was specifically detected PCV4 but not other PCVs and porcine pathogens, indicating that the newly designed primers/probe set is specific to the PCV4 Cap gene. Furthermore, GAPDH was stably amplified by the dqPCR in all tested viral and clinical samples containing pig cellular materials, indicating the high reliability of the dqPCR assay. The limit of detection of the assay 5 copies of the target PCV4 genes, but the sensitivity of the assay was higher than that of the previously described assays. The assay demonstrated high repeatability and reproducibility, with coefficients of intra-assay and inter-assay variation of less than 1.0%. Clinical evaluation using 102 diseased pig samples from 18 pig farms showed that PCV4 circulated in the Korean pig population. The detection rate of PCV4 obtained using the newly developed dqPCR was 26.5% (27/102), which was higher than that obtained using the previously described cPCR and TaqMan probe-based qPCR and similar to that obtained using the previously described SYBR Green-based qPCR. The dqPCR assay with IPC is highly specific, sensitive, and reliable for detecting PCV4 from clinical samples, and it will be useful for etiological diagnosis, epidemiological study, and control of the PCV4 infections.

• Journal of Practical Agriculture & Fisheries Research
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• v.11 no.1
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• pp.137-158
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• 2009

This study is to find the causes of the current situations of conflict between generations in regards to succession of their family farm, for the target group of graduates Korea National Agricultural College of the year 2008 and their parents. This study aims at finding a way of controlling and solving the conflicts, and of developing a course of education and training, so that through this process they can come to a rational conclusion to the conflicts that arise regarding succession of the farm, in a climate of harmony and peace. It is found that communication between parents and graduates has normally gone on well, but specific problems related to management of the farm are often present. Furthermore, there is often lack of trust and promise between the parties which often causes difficulties in preparation for the succession of the farm. On the basis of these observation, we have designed and implemented an education workshop and training, as a program in which parents and their successors participated. As a result, we found it to be very effective, but it was also found to be in need of some changes. The workshop is to be implemented in two separate stages. The first stage should focus on communication and trust between family members. Firstly, they are given the opportunity to share the list of concerns withone another, as an ice breaking activity. Secondly, they can present their own hopes or wishes. And lastly, they can communicate with one another in an effort to find resolutions that will be keep both parties satisfied. The second stage should be aimed at establishing agreements concerning succession of the farm in a harmonious and peaceful manor; the second stage is also an opportunity to discuss 'Farm management and succession'. The Korea National Agricultural College (KNAC) is in the pursuit of fostering agricultural CEO's for the future of Korea. KNAC is currently implementing a very unique system of interviews in which parents participate together with students, in order to help them make a plan for rational management of their farm and smooth succession of the farm. Although KNAC now has students present a blueprint of their own unique business plans as a graduation thesis, it is necessary for KNAC to complement this system with education and training regarding the succession of family farms. Furthermore, KNAC should also develop an education and training program that is separate for this purpose, and make it a regular course of study of KNAC in the future.

• Journal of Practical Agriculture & Fisheries Research
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• v.10 no.1
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• pp.3-27
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• 2008

This study is to find the causes of the current situations of conflict between generations in regards to succession of their family farm, for the target group of graduates of the year 2008 and their parents. This study also aims at finding a way of controlling and solving the conflicts, and of developing a course of education and training, so that through this process they can come to a rational conclusion to the conflicts that arise regarding succession of the farm, in a climate of harmony and peace. It is found that communication between parents and graduates has normally gone on well, but specific problems related to management of the farm are often present. Furthermore, there is often lack of trust and promise between the parties which often causes difficulties in preparation for the succession of the farm. On the basis of these observation, we have designed and implemented an education workshop and training, as a program in which parents and their successors participated. As a result, we found it to be very effective, but it was also found to be in need of some changes. The workshop is to be implemented in two separate stages. The first stage should focus on communication and trust between family members. Firstly, they are given the opportunity to share the list of concerns withone another, as an ice breaking activity. Secondly, they can present their own hopes or wishes. And lastly, they can communicate with one another in an effort to find resolutions that will be keep both parties satisfied. The second stage should be aimed at establishing agreements concerning succession of the farm in a harmonious and peaceful manor; the second stage is also an opportunity to discuss 'Farm management and succession'. The Korea National Agricultural College (KNAC), as a state college, is in the pursuit of fostering agricultural CEO's for the future of Korea. KNAC is currently implementing a very unique system of interviews in which parents participate together with students, in order to help them make a plan for rational management of their farm and smooth succession of the farm. Although KNAC now has students present a blueprint of their own unique business plans as a graduation thesis, it is necessary for KNAC to complement this system with education and training regarding the succession of family farms. Furthermore, KNAC should also develop an education and training program that is separate for this purpose, and make it a regular course of study of KNAC in the future.

• Research in Plant Disease
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• v.29 no.4
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• pp.414-419
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• 2023

In 2023, a number of seeds suspected to be discolored black oat seeds on oat farms in Gangjin were observed and examined for fungal infection. The species Alternaria alternata was predominant, accounting for 84% of all fungal infections. The appearance and quality of seeds harvested in 2022 were compared with seeds harvested in 2023 from the same field. The lightness value was lower in the seeds harvested in 2023, while the electrical conductivity was higher in the seeds harvested in 2023. The content of avenanthramide was found to be 10 times higher in the 2023 seeds than in those harvested in 2022. The accumulated precipitation in Gangjin in May 2023 was 230 times higher than that in May 2022, and the average relative humidity was high. These conditions created an environment suitable for infection of A. alternata, which were thought to have caused discolored black oat seeds.

• Journal of Bio-Environment Control
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• v.32 no.4
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• pp.442-448
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• 2023

This study aimed to develop an optimal greenhouse model for strawberry seedling during the summer high-temperature period based on the results of field surveys. We conducted a survey on the structure types of 46 strawberry seedling farms nationwide, including width, ridge height, eaves height, ventilation method, seedling bed width, and spacing. Based on the survey results, we derived the optimal greenhouse model by considering various factors. The greenhouse width was set at 14 meters to maximize the efficiency of seedling beds and overall space. The height was determined at 2 meters, taking into account ventilation during the summer season. To reduce stress on the supporting structure due to snow loads, we established a reinforcement installation angle of 50 degrees. We analyzed two different models that use support beams with dimensions of φ48.1×2.1t and φ59.9×3.2t, respectively, to ensure structural safety against meteorological disasters, considering regional design wind speeds and snow accumulation. We utilized these developed greenhouse model to conduct strawberry seedling experiments, resulting in a high survival rate of average 93.2%. These findings confirm the usefulness of the strawberry seedling greenhouse in improving the seedling environment and enhancing overall efficiency.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.1
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• pp.1-8
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• 2022

In order to manufacture feed suitable for consumer use and provide feed value information, we analyzed the feed components of the four main forage rice varieties by plant parts harvested 30 days after heading. The contents of the six feed ingredients were significantly different (p<0.05) among harvested parts. In the panicle, the crude protein (CP) (6.97%) and lignin (3.11%) were the highest, while the crude ash (CA) and neutral detergent fiber (NDF) contents were significantly lower, resulting in a total digestible nutrient (TDN) content of 77.29%, which is higher than that of the stem (64.82%) and leaf blade and sheath (LBS) (63.57%) (p<0.05). In contrast, the content of crude fat (CF) did not differ significantly among parts (p<0.05). In panicles from 'Jonong', 'Nokyang' and 'Yeongwoo', the TDN content of each cultivar was 78.48-79.07%, with no significant difference among the varieties. In 'Mogwoo' (Mw), the CP content was 8.70%, which was much higher than that of other varieties (p<0.05). In particular, the Mw TDN content was slightly lower in the panicle (72.95%) but higher in the stem (75.37%) and LBS (66.49%) than in the other varieties. The CA, NDF, acid detergent fiber (ADF), and lignin contents were also very low compared to other varieties; therefore, the feed value of the stem and LBS was excellent. In addition, the total dry matter weight (DMW) was 123 g per hill, which was much higher than 82-105 g per hill for other varieties. The distribution of DMW by part was LBS (56.9 g), stem (36.8 g), and panicle (29.3 g), and because the parts, except the panicles, were much higher than the 43-57% of other varieties (grain straw ratio: 76%), rice straw is advantageous in terms of quantity and feed value when used as forage on farms. The relative feed value (RFV) of the four cultivars ranged from 86.79-403.74 across all parts, and hay of grade 3 or higher with an RFV of 100 or more increased with delayed heading in both stems and LBS. This is due to the accumulation of starch into grains during ripening, which supports the observation that the RFV of the early flowering 'Jonong' and 'Nokyang' panicles increased.

• Journal of Korean Society of Forest Science
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• v.90 no.4
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• pp.458-464
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• 2001

In this study, the annual growth of roots and their branching forms of Norway spruce(Picea abies [L.] Karst.) were analysed to compare the development of their root in the differently acidified forest soils. And there was no significant difference among the stands for the modified roots and the non-modified roots depending on the root branch forms, and however in the most acidified Weidenbrunnen stand, the modified roots, the abnormal root branch form such as fork, gun and rake types were appeared. As a result of the ring of the root, the annual horizontal root growth were 6.3cm for Weidenbrunnen and Barbis stands and 9.5cm for Eberg$\ddot{o}$tzen stand. The average annual vertical root growth was 4.4cm, 5.4cm, and 6.7cm for Weidenbrunnen stand, Barbis stand, and Eberg$\ddot{o}$tzen stand, respectively. The cross section area by root distribution at 80cm deep showed that the thick and thin roots were evenly distributed in of Eberg$\ddot{o}$tzen stand and the sum of root cross section area was $32.6cm^2$. In Barbis stand, the thick roots were distributed in the center while the thin roots were comparatively rare. And the sum of root cross section area was $29.2cm^2$. In Weidenbrunnen stand, only a few thin roots were found, and the total root cross section area was $10.9cm^2$. The stability coefficient of roots were in the order of Eberg$\ddot{o}$tzen stand(1.04), Barbis stand (0.3), and Weidenbrunnen(0.08) stand. Among the investigated Norway spruce stands, the modified abnormal root branching form and the low root growth appeared in the Weidenbrunnen stand could be attributed by the soil acidification etc.

• Applied Biological Chemistry
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• v.48 no.1
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• pp.23-33
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• 2005

Agricultural sciences field in South Korea has many strong points such as numerous researchers, establishment of research infra-structure, excellence in research competitiveness and high technological level. However, there are also many weaknesses including insufficient leadership at related societies and institutes, deficiency of the next generation research group, and insufficiency in research productivity. There are many opportunities including increasing the importance of the biotechnological industry, activating international cooperation researches, and exploring the multitude of possible research areas to be studied. However, some threats still exist, such as pressure from the government of developed countries to open the agricultural market, the decrease of specialized farms, and intensification for researches to gratify economic and social demands. To encourage research activities in the agricultural sciences field in Korea, the following actions and systems are required: 1) formulation of a mid- and a long-term research master plan, 2) development of a database on the man power in related fields, 3) activation of top-down research topics, and associated increase of individual research grants, 4) development of special national programs for basic researches in agricultural sciences, 5) organization of a committee for policy and planning within the related societies, and 6) system development for the fair evaluation of the research results.