• The Journal of Fisheries Business Administration
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• v.29 no.1
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• pp.121-137
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• 1998

This study was conducted to examine the economic evaluation of the newly developed fish meal analog (BAIFA-M) in Korean rockfish feed. A raw fish feed (MP) and two commercially formulated diets (EP) were employed to compare weight gain (WG), feed conversion ratio (FCR) and survival rate (SR) from the sea cage culture system. By using the economic model in the practical sea cage culture system, feed cost, production cost and gross profit per kg production, rate of profit to gross revenue (RPGR), and internal rate of return (IRR) were calculated based upon the results of the experiment and the information of the private aquaculture farm (Young Chang) in Tong young, Korean. IRR criteria is one of the popular economic feasibility analysis methods applicable far aquaculture industry. This is an economic evaluation method to compare the given interest rate or the discount rate with IRR which can be calculated by the difference between the present value of the benefit stream and of the cost stream. The benefits of using EP on WG, FCR, SR, and production cost will be emphasized in this study. Fish averaging 20$\pm$3.6g (Mean$\pm$SD) were randomly distributed in each small cage (6m$\times$6m) as groups of 2,000 fish. By using 3 large size cages (12m$\times$12m), 12 small cages were constructed, and only 9 small cages were employed for three replicates of each diet treatment. To compare with MP diet, two sinking EP diets were designed by our laboratory and produced by the local feed company who wanted to promote these EP diets for the mass cage culture of Korean rockfish in the future. Two EP diets contain white fish meal and/or BAIFA-M as the main animal protein sources : WFM diet, maximum 43% of white fish meal : BAIEA- M diet, 30% of white fish meal nab replaced by BAIFA- M from WFM diet. Results are summarized in Table 1. Fish fed MP diet showed significantly lower SR than does fish fed two EP diets(P<0.05). However, there Were no significant difference on FCR among fish fed three practical diets. Table 1. Average feed conversion ratio (FCR), accumulative average survival rate (SR) and economic evaluation data far three practical diets. As we expected, BAIFA-M diet is more economical than WFM diet as well as MP diet. Feed cost and production cost per kg production from BAIEA - M diet were lower than those from WFM and MP diets. Moreover, gross profit per Kg production, RPGR and IRR from BAIFA- M diet were higher than those from WFM and MP diets. This economic evaluation study clearly indicated that MP diet should be replaced by the commerical formulated EP diets as soon as possible in the near future because MP diet is not economical in the practical sea cage culture system.

• Journal of Embryo Transfer
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• v.32 no.3
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• pp.171-176
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• 2017

This study was conducted to investigate the breeding status of farms to improve the production efficiency of Hanwoo calf. The study was conducted on 45 farms divided into two groups. This study was conducted to investigate the breeding size and breeding area of Hanwoo cows. The average age at first delivery of Hanwoo was 28.7 months. The number of artificial insemination per pregnancy was $1.45{\pm}0.32$, and the number of artificial insemination days after birth was 119.8 days. Conception rates were $75.2{\pm}16.93%$ for small farms and $70.6{\pm}17.46%$ for medium sized farms and $71.4{\pm}11.03%$ for large farms. When we looked at farming methods, 'the farmers using estrus observation aids' had 10.42% higher calf production rate than the 'unused farmers'. The farms vaccinated with IBR and BVDV for breeding cattle showed a 4.41% decrease in abortion, stillbirth and mortality. According to farming conditions, conception rate and delivery rate improved by 3.47% and 18.29%, respectively, when grazing and exercising were performed. Observation, immunization and grazing were found to be important indicators for improving calf production efficiency in Hanwoo farm. This study can be used as a research data to improve the reproductive rate of farmhouse sites through the survey on the breeding status of Hanwoo farmers.

• Reproductive and Developmental Biology
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• v.37 no.4
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• pp.263-267
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• 2013

Pig producers have been shown keen interest of the number of spermatozoa in a semen dose since pig artificial insemination introduce. However, determining the minimal number of spermatozoa need per AI without detrimental effect on overall reproductive performances is not an easy question to answer. To increase the efficiency of semen utilization in pig AI, optimum number of spermatozoa per dose needed to determine. The objective of this study was to determine the reproductive performance and factors that affect on-farm application of low-dose semen insemination in sows. Data were collected from Darby Genetics AI studs from 4th of June to 7th of July, 2012 (n=401). The numbers of parturition were 84, 234 and 83 in sows inseminated with doses of $1.5{\times}10^9$, $2.0{\times}10^9$ and $2.5{\times}10^9$ spermatozoa in 100ml extender, respectively. There were no significant differences on reproductive performances such as gestation period, total born, total born alive, stillbirth and mummy in sows inseminated with different semen doses. The average number of born alive was 10.5, 11.0 and 10.4 from sows inseminated with $1.5{\times}10^9$, $2.0{\times}10^9$ and $2.5{\times}10^9$ sperms, respectively. Also, number of spermatozoa per dose did not affect litter size (p>0.10). There were no significant differences of maternal genetic line difference on gestation period, total number born, number born alive, born dead and mummy. The estimated correlation coefficients of the different semen doses with total number born, number born alive, born dead and mummy were r=-0.00, -0.01, 0.02 and 0.02, respectively. Taken together, the result of this study suggested that when semen was appropriately inseminated after induced ovulation, insemination with low-dose ($1.5{\sim}2.0{\times}10^9$) semen dose not adversely affect sow's fertility.

• Journal of Sericultural and Entomological Science
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• v.14 no.2
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• pp.95-103
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• 1972

The major purpose of this study is to collect the information related on the aspects of economic efficiency for solving the problems which are faced by farmers and areas, and providing scientific facts to farmers and related institutions for further development of sericultural sector in Korea. In order for obtaining the related information 12 sample areas among 23 major sericultural farming areas and 30 farm units in each area are selected and analyzed in this study. The fold suevey is made by member of this study team and graduate students in the Department of Sericultural Science with a prepared questionnaires. Cross-section and regression analysis methods are employed for processing the data in this study. The major findings obtained are as followings. 1. Sericultural earnings per Tanbo is, on the average, 22, 752 won in new cultivated areas and 29, 403 won in ordinary ones. There are big difference in the size of earnings by areas, especially, 46, 968 won in Kumo mountain area, compared with 16, 798 won in Yeoju and Yichun areas. General trend is finded that small scale farming units are made higher earnings and operating their farms efficiently. 2. Cocoon production expences per Tanbo is 16, 737 won in new cultivated areas and 19, 802 won in ordinary areas. There are also big difference in farming expences, especially, 27, 389 won in Sudang area, compared with 11, 689 won in Emjin area. 3. Sericultural income per Tanto is 10, 664 won in ordinary areas and 6, 898 won in new cultivated areas. Farmers in Kumo mountain area make the highest income of 21, 164 won and lowest income of 1, 296 won in Sudang area. It can be generized that about 30-50 a sized farmers make higher income. 4. Land, labor and capital productivities estimated by fitting Cobb-Douglas functions in ordinary areas are higher than in new cultivated areas, especially, labor productivity is higher in ordinary areas. 5. Changsung, Kwangna, Yunsun and Kumo mountain areas are technically and economically efficient. Sudang and Mujinchang areas are technically successful but economically inefficient and Emjin and Honam areas are technically inefficient but economically efficient. YeojuYichun, Chunwon and West Kyongnam are technically and economically inefficient. Technical and economic improvement program should be implemented for these areas. 6. Estimated Internal Rate of Return (IRR) on capital investment in Chongwon are is 23.5 percent. It is economically feasible, if we consider 20 percent of opportunity cost of capital in our economy.

• Research in Plant Disease
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• v.12 no.2
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• pp.115-118
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• 2006

In February of 2000-2001, the gray mold disease occurred on nephrolepis (Nephrolepis sp.) grown in a flower nursery farm in Suwen, Korea. Typical symptoms were water-soaked brown or blackish lesions on terminal leaf blades. Severely infected leaves were entirely blighted with grayish fungal mycelia formed on the surface. Conidia of the fungus in mass were hyaline or gray, 1-celled, mostly ellipsoid or ovoid and $13.5{\sim}16.9{\times}6.8{\sim}9.2{\mu}m$ in size. Conidiophores were formed on PDA with $8.7{\sim}11.1{\mu}m$ in width. The sclerotia were readily formed within 2 or 3 days on PDA. In addition, the Biolog database gave the causal fungus a high similarity to Botrytis cinerea (78%) with a match probability of 100%. Pathogenicity of the causal organism was proved according to Koch's postulate. The causal organism was identified as Eotrytis cinerea based on its mycological characteristics and utilization of carbon sources with Biolog system as supporting data. This is the first report of gray mold of nephrolepis caused by Botrytis cinerea in Korea.

• Horticultural Science & Technology
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• v.33 no.5
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• pp.789-795
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• 2015

The new garden chrysanthemum (Dendranthema grandiflorum Ramat.) cultivar 'Nuri Ball' was developed at Yesan Chrysanthemum Experiment Station of Chungcheongnam-do Agricultural Research and Extension Services in 2011. 'Nuri Ball' was bred through a cross between the '02-145-01' line as the female parent with yellow flower color and '02-04-32' as the male plant with white flower color in 2004. Three years of adaptation trials were conducted from 2006 to 2009 under natural conditions. This study compared the external shape type with that of 'White Miri' and conducted ploidy and RAPD (Random amplified polymorphic DNA) marker analyses. These tests showed that 'Nuri Ball' cultivar has its own characteristics compared with the control 'White Miri'. 'Nuri Ball' was a shrub type variety with semi-double flowers of 4.0 cm in width with white petals. It could produce 1025.2 flowers per plant in autumn. Compared with the control 'White Miri', 'Nuri Ball' was similar in terms of shape and color of flowers, but was different in flower size and number. The natural flowering time of 'Nuri Ball' was late September. It had very vigorous growth and an early budding plant. 'Nuri Ball' was demonstrated to be a new cultivar based on ploidy test and RAPD analysis. 'Nuri Ball' is intended for use as a bed chrysanthemum and expected to contribute to farm incomes in landscaping.

• FLOWER RESEARCH JOURNAL
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• v.16 no.1
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• pp.63-70
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• 2008

This experiment was conducted to acquire the basic data necessary for the artificial pond greening. Eighty four hydrophytes collected from 11 domestic small ponds and a farm were used in this experiment. The size of the artificial pond used was $6m{\times}3m{\times}1.5m(length{\times}width{\times}depth)$. Twelve months after planting, species were selected for their high ornamental values and tissue contents of N and P in each month. Tissue contents of N in Trapha nantan, Nymphoides indica, Nymphaea hybrid, and Murdannia keisak were high. Tissue contents of P in Monochoria vaginalis and Murdannia keisak were also high. The pH of artificial pond stabilized at a 6.8~7.6 range from May 2005 to March 2007. The EC was low in summer and high in autumn. From April to October, 5, 19, 23, 32, 31, 28, and 26 species, respectively, were selected for artificial pond greening. One year after planting, vegetation changed from 78 species (Potamogeton octqandrus, Salvinia natans, Potamogeton malaianus, etc.) to 38 species (Scirpus tarbernaemontani, Scirpus karuizawensis, Scirpus triqueter, etc.). Species diversity in the artificial pond was as follows, indicating it being a stabilized artificial pond; 38 species, 1,437 total number of plants, species richness index of 11.72, and maximum diversity index of 0.97.

• Animal Bioscience
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• v.34 no.7
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• pp.1105-1115
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• 2021

Objective: To conserve and utilize the genetic resources of a traditional Chinese indigenous pig breed, Liangshan pig, we assessed the genetic diversity, genetic structure, and genetic distance in this study. Methods: We used 50K single nucleotide polymorphism (SNP) chip for SNP detection of 139 individuals in the Liangshan Pig Conservation Farm. Results: The genetically closed conserved population consisted of five overlapping generations, and the total effective content of the population (Ne) was 15. The whole population was divided into five boar families and one non-boar family. Among them, the effective size of each generation subpopulation continuously decreased. However, the proportion of polymorphic markers (P_N) first decreased and then increased. The average genetic distance of these 139 Liangshan pigs was 0.2823±0.0259, and the average genetic distance of the 14 boars was 0.2723±0.0384. Thus, it can be deduced that the genetic distance changed from generation to generation. In the conserved population, 983 runs of homozygosity (ROH) were detected, and the majority of ROH (80%) were within 100 Mb. The inbreeding coefficient calculated based on ROH showed an average value of 0.026 for the whole population. In addition, the inbreeding coefficient of each generation subpopulation initially increased and then decreased. In the pedigree of the whole conserved population, the error rate of paternal information was more than 11.35% while the maternal information was more than 2.13%. Conclusion: This molecular study of the population genetic structure of Liangshan pig showed loss of genetic diversity during the closed cross-generation reproduction process. It is necessary to improve the mating plan or introduce new outside blood to ensure long-term preservation of Liangshan pig.

• Journal of Mushroom
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• v.18 no.4
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• pp.297-302
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• 2020

Five varieties of mushrooms, including Sae-do, were examined using farm field tests to determine their morphological characteristics and quality by performing harvest flush. Considering the cultivation characteristics of the varieties studied, the parts related to mushroom generation and production showed almost similar characteristics. Overall, the mycelial forces were similar; however, in the evaluation of plantation tests performed by farmers, "saedo" was found to be the strongest and "saehan" was considered to be the weakest. Weights of fruiting bodies were related more for compost status and regimen of use than for breeding, and it was difficult to distinguish between the weights of fruiting bodies of the varieties studied. Regardless of the variety, pileus diameter, pileus thickness, and stem length of Dalseong-gun, Yongin-si, and Boryeong-si decreased as the harvest flush progressed. However, stem thickness tended to increase in the second and third flush compared to that in the first flush, regardless of the variety. However, the Gyeongju-si farms could not identify any trends attributable to varieties and harvest flushes. The pileus size and stem length of the fruiting bodies of varieties from Buyeo farms decreased with the progression of the harvest flush. However, pileus thickness and stem thickness did not show any specific tendency of growth among the varieties studied. The differences in the morphological characteristics of mushroom varieties in each harvest cycle are expected to be caused by differences in the supply of nutrients in the medium, the quality of the compost used, and the cultivation environment rather than the variety.

• Journal of Animal Science and Technology
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• v.64 no.1
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• pp.1-9
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• 2022

Equilume light masks had no impact on hastening the resumption of estrous cyclicity in mares maintained in outdoor pastures on the mainland of Korea due to the cold weather conditions. Jeju Island is a major horse-breeding site in Korea and is warmer than the mainland during the winter season. Therefore, the primary objective of this study was to explore the efficiency of the Equilume light mask on the resumption of seasonal estrous cycles in Thoroughbred mares on Jeju Island. A total of 20 nonpregnant mares were randomly divided into the Equilume light mask (n = 9) and stable lighting (n =11) groups. The experiment was performed at seven different horse-breeding farms located on Jeju Island from November 15, 2020, to February 15, 2021. The mares were exposed to the respective lights from 16:00 to 23:00. Follicle size and uterine edema were measured by ultrasound scanning. Body condition scores (BCS) were also monitored during the experiment. Statistical analysis was conducted using the SAS and SPSS software, and p-values of < 0.05 were considered statistically significant. Two of the nine (22.2%) mares in the Equilume light mask group and three of the 11 (27.28%) mares in the stable lighting group were still cycling in December and January, which were considered as all-year-round cycling mares. On February 15, there was no difference between groups in the resumption of early seasonal estrus cycle, which was determined by follicles > 25 mm in addition to uterine edema. All mares in the Equilume light mask group and five of the eight mares (62.5%) in the stable lighting group had resumed cycling. Interestingly, six of the seven mares (87.5%) in the Equilume light mask and four of eight mares (50%) in the stable lighting group had already ovulated on February 15 (p > 0.05), as determined by the presence of a recent corpus luteum. No difference was observed in BCS and uterine edema between groups (p > 0.05). In conclusion, the Equilume light mask can be an effective approach to induce early seasonal estrus cycles of mares in Jeju Island, and it also enhances the efficiency of farm management by reducing labor.