• Korean Journal of Agricultural Science
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• v.25 no.2
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• pp.216-224
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• 1998

This study was performed to offer the basic and applicable data for improvement of Korean cattle and dairy cattle, according to finding the genetic construction obtained from analysis of genetic polymorphisms of ${\beta}$-lactoglobulin and ${\kappa}$-casein loci related Korean cattle and Holstein cows using PCR-RFLP. Genomic DNA used in this study was prepared from the blood of 253 individuals of Korean cattle in Korean Native Cattle Improvement Center, NLCF, and the blood of 113 individuals of Holstein cows in National Livestock Research Institute. The results obtained are summarized as follows : 1. This study confirmed amplified products of 530bp and 262bp fragments obtained from the amplification of ${\beta}$-lactoglobulin and ${\kappa}$-casein loci in Korean cattle and Holstein breed by PCR. 2. The ${\beta}$-lactoglobulin AA genotype showed 153bp and 109bp fragments, and ${\beta}$-lactoglobulin AB genotype showed 153bp, 109bp, 79bp and 74bp fragments, and BB genotype showed 109bp, 79bp and 74bp fragments in amplified products of ${\beta}$-lactoglobulin loci with the restricted enzyme digestion of Hae III. 3. The ${\kappa}$-casein AA genotype showed a 530bp fragment, and ${\kappa}$-casein AB genotype showed 530bp, 344bp and 186bp fragments, and BB genotype showed 344bp and 186bp fragments in amplified products of ${\kappa}$-casein loci with the restricted enzyme digestion of Taq I. 4. On ${\beta}$-lactoglobulin genotypes and gene frequencies, Korean cattle were 6.72%, 26.09% and 67.19% for AA, AB and BB genotypes, and ${\beta}$-lactoglobulin A and B alleles were 0.197 and 0.803, and Holstein were 35.40%, 56.64% and 7.96% for AA, AB and BB genotypes, and ${\beta}$-lactoglobulin A and B alleles were 0.637 and 0.363, respectively. 5. On ${\kappa}$-casein genotypes and gene frequencies, Korean cattle were 46.25%, 39.13% and 14.62% for AA, AB and BB genotypes, and ${\kappa}$-casein A and B alleles were 0.658 and 0.342, and Holstein were 60.18% and 38.94% and 0.88% for AA, AB and BB genotypes, and ${\kappa}$-casein A and B alleles were 0.796 and 0.204, respectively. 6. As a consequence, the gene frequency was 0.197 and 0.803 for ${\beta}$-lactoglobulin A and B alleles, and 0.658 and 0.342 for ${\kappa}$-casein A and B alleles in Korea cattle, but was 0.637 and 0.363 for ${\beta}$-lactoglobulin A and B alleles, and 0.796 and 0.204 for ${\kappa}$-casein A and B alleles in Holstein, respectively.

• Journal of Animal Science and Technology
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• v.47 no.6
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• pp.963-974
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• 2005

This study was conducted to examine the growth performance, carcass characteristics, physico-chemical properties and fatty acid composition of muscle tissues of Hanwoo steers when they were fed diets containing four levels of E. ulmoides leaves. Steers were allotted to one of four dietary treatments, which were designed to progressively substitute Eucommia ulmoides for 0, 3, 5 and 10% of the rice straw in the basal diet. Seventy two Hanwoo steers (321±13kg) were used. Average daily gain (0.81-0.86kg) and feed conversion (10.05-10.59) were not changed by feeding E. ulmoides leaves. Emission of fecal ammonia gas was decreased by increasing substitution levels of E. ulmoides leaves. Emission of ammonia gas in feces of steers were significantly (p<0.05) decreased in the 5% and 10% treatments at 40℃ compared with in control (30.6ppm) and 3% treatment (29.8ppm), respectively 20.3 and 21.6ppm. Back fat thickness was higher (p<0.05) in steers fed control diet (15.0mm) than 5 and 10% E. ulmoides diets (10.2 and 10.5mm respectively). The grade ‘A’ appearances of meat yield of steers were increased up to 20% by the 3% substitution of E. ulmoides leaves, and the grades ‘1+’ and ‘1’ appearances of meat quality were significantly improved (p<0.05) by the 5 and 10% Eucommia ulmoides feeding. There was no statistical difference in meat color of loin and top round among all treatments. It appeared that the 5% and 10% E. ulmoides leaves feeding affected (p<0.05) a increase in oleic acid concentration in loin and top round muscles. The concentration of serum cholesterol was lower (p<0.05) in steers fed 10% E. ulmoides (53.3mg/100g) than that of the other treatments (55.7-57.0mg/100g). The diarrhea incidence was about 20.26% in control, while it was lower (p<0.05) in the 5 and 10% E. ulmoides leaves treatments (10.4-12.5%) than control. There was no statistical difference in the occurrences of respiratory disease among all treatments. It is concluded that E. ulmoides leaves should be a prospective feed additive because it contains various functional substances. It is likely that air-dried E. ulmoides leaves can reduce the back fat thickness of Hanwoo steers and the occurrences of diarrhea. Therefore, the 5 and 10% substitution of E. ulmoides for roughage are highly recommended to be used in practice.

• Korean Journal of Agricultural Science
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• v.36 no.2
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• pp.167-177
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• 2009

This study was conducted to characterize the DGAT1 gene in Korean Holstein dairy cattle population and examine the relationship of DGAT1 polymorphisms with milk yield and milk fat yield for the genetic improvement of Korean Holstein dairy cattle. Results indicated that the 411 bp PCR products were successfully amplified by DGAT1 specific primers. Sequence analysis indicated that the DGTA1 Q allele had AUG (Lysine, K) nucleotide sequences in 216-218 bp and q allele had GCG (Alanine, A) sequences in the same position. Nucleotide sequence homology between the DGAT1 sequences generated in this study showed 100% homology with bovine DGAT1 sequences in the NCBI database. The genotype frequencies of DGAT1 QQ, Qq, and qq were 16.43, 36.43, and 47.14%, respectively, in Korean Holstein dairy cattle population. The observed Q and q allele frequencies were 0.35 and 0.65, respectively. Statistically significant (P<0.05) results were identified for milk yield and milk fat yield for the DGAT1 genotypes. The Qq genotype Holsteins have significantly higher milk yield and milk fat yield than those of the QQ and qq genotype Holsteins(P<0.05).

• Korean Journal of Poultry Science
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• v.42 no.1
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• pp.33-40
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• 2015

This study was conducted to investigate the effects of dietary quercetin on growth performance, blood biochemical parameters, immunoglobulin, and blood antioxidant activity in broiler chickens. Three hundred twenty one-day old Ross broilers were divided 8 treatments (C(-), basal diet; C(+), basal diet with antibiotics; vitamin E 20 IU; vitamin E 200 IU; quercetin 20 ppm; quercetin 200 ppm; methoxylated quercetin 20 ppm; methoxylated quercetin 200 ppm) with 4 replicates and 10 birds per replicate. Birds were reared for 35 days and their feed intake and weight gain were measured weekly. At 35d, eight birds of average weight from each replicate were selected for blood collection and analysis. Weight gain of birds in the groups fed quercetin was higher when compare to NC but there was no significant difference. In the serum, creatinine, BUN and AST in quercetin groups significantly decreased compared to those of control (NC and PC) (P<0.05). The contents of IgA and IgM were significantly lower in quercetin groups than those of NC (P<0.05). SOD like activity and MDA content tended to decrease in quercetin groups, however, there was no significant difference among treatments. In conclusion, supplemental quercetin to poultry diet could be positive aspect on performance and blood metabolites. Optimum adding levels was more than 20 ppm.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.4
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• pp.295-300
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• 2008

This experiment was conducted to compare forage production and feed value of winter forage crops at the experimental field of Livestock Division, National Institute of Animal Science from 2003 to 2004 in Jeju. The experiment was arranged in slit plot design with three replications. Main plots consisted of two cutting times, one time cutting and two times cutting. Sub plots consisted of 5 different seed combinations, T1 (Italian ryegrass), T2 (Oat), T3 (Italian ryegrass 25+Oat 75%), T4 (Italian ryegrass 50+Oat 50%), T5 (Italian ryegrass 75+Oat 25%). One time cutting showed the highest dry matter (DM) yield by 18,680 kg/ha. Tow times cutting showed the highest crude protein (CP) content by 11.97%. The all treatments have narrow range of total digestible nutrient (TDN) from 60.6% to 70.4%.

• Journal of Life Science
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• v.20 no.12
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• pp.1896-1901
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• 2010

This study was conducted using quantitative real-time PCR using Lactobacilli as probiotics. Quantitative real-time PCR (RT PCR) was conducted via a method involving SYBR Green 1 and a probe. Plasmid DNA was cloned using the 16S-23S rRNA intergenic species region. Gene clones were diluted from $10^2$ to $10^{10}$. Standard curves were constructed via Ct values obtained from the results of Real-time PCR via the aforementioned SYBR Green 1 and probe method. Plasmid DNA was also cloned using the 16S-23S rRNA intergenic species region and the gene clones were diluted from $10^2$ to $10^{10}$ copy numbers via the probe method. Using RT PCR, a standard curve of plasmid DNA copy numbers was also determined. The slope value for the Y-axis intercept and $R^2$ value were measured as -3.346, 33.18, and 0.993, respectively, via the first method. For the second method, the slope value for the Y-axis intercept and $R^2$ were -3.321, 31.10 and 0.995, respectively. The PCR inhibitor could not express the detection curve at a copy number over $10^{10}$ via either method, owing to high DNA density. The DNA extract from probiotics was diluted without pre-culturing, and 16 products were amplified via both methods. The Ct value was 11.06~18.12 in the first method and 16.74~22.11 in the second method. Measured probiotics and log copy values were largely similar among the methods used. It was concluded that both methods are effective for analysis, but further research will be required to verify the optimal method.

• Food Science of Animal Resources
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• v.29 no.5
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• pp.627-632
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• 2009

The objective of this study was to investigate the supplementation effect of selenium on beef color stability. A total of 15 Hanwoo steers were divided into 3 groups and 2 groups were administered with 0.9 ppm of one of two organic-selenium products, Organic-Se and Se-SMC (Se-spent mushroom compost) for 4 mon. The third group was the control group, which was not with fed selenium during the same period. The result of this study showed that there was no significant difference in meat color between the control and treatments when Hunter $L^*$, $a^*$, $b^*$, chroma, hue and total color difference (${\Delta}E$) were measured after 30 min of blooming. When the oxymyoglobin (OxyMb) contents were measured after beef samples were ground and stored for 48 h at $20^{\circ}C$ in an incubator, they were 26.04%, 28.52% and 33.78% for the control, Organic-Se and Se-SMC after 14 d of storage and 12.65, 18.98 and 18.72 after 21 d of storage at $4^{\circ}C$, respectively (p<0.05). The control had a significantly higher metmyoglobin (MetMb) content than Organic-Se and Se-SMC (p<0.05). This result indicated that selenium supplementation was effective in preventing the oxidation of myoglobin(Mb) and production of MetMb and thus was able to maintain the purplish fresh red color of the meat.

• Korean Journal of Poultry Science
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• v.37 no.3
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• pp.255-263
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• 2010

Inclusion body hepatitis-hydropericardium syndrome (IBH-HPS) is an acute viral disease usually found in broilers aged from 3 to 5 weeks and causes up to 75% mortality. Among the 12 serotypes of fowl adenovirus group 1, serotype-4 (FAdV-4) was identified as a primary agent of IBH-HPS and was usually isolated in IBH-HPS cases in Korea since 2007. To prevent these IBH-HPS outbreaks in Korea, we developed the FAdV-4 inactivated vaccine using Korean isolate (ADL070244) and evaluated the efficacy of this vaccine. For the efficacy test, 2-week-old specific-pathogen-free (SPF) chickens intramuscularly inoculated with 1 or 2 dose of inactivated vaccine were used and challenged with FAdV-4 through either intramuscular or oral route at 2 weeks after vaccination. The vaccine induced good seroconversion which was confirmed by agar gel precipitation (AGP) test. In addition, the vaccine could decrease the FAdV-4 detection rate and histological lesion severity such as lymphocyte infiltration and necrosis in the liver comparing with those of non-vaccination group. Based on the current results, the developed FAdV-4 inactivated vaccine in this study was effective in the terms of reduction of virus detection rate and histological lesions severity. However, it was difficult to confirm the efficacy of the vaccine clearly because of no mortality and clinical signs in the non-vaccinated group after challenge. Therefore, we need further study to develop a standard challenged model system which could clearly evaluate the efficacy of the vaccines for FAdV-4.

• Journal of Applied Biological Chemistry
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• v.61 no.2
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• pp.195-204
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• 2018

Pesticide residue in the eggs in the market has become a significant problem in Korea. In particular, the detection of fipronil indicated that unregulated pesticide residue can be present in livestock products, including eggs. Institutionally unregulated pesticides are a risk to human health and the ecosystem. In this study, we analyzed the system of agricultural pesticide management in Korea, the European Union, and the United States of America (USA) and discussed the problems of the Korean management system and the possible improvement directions. Based on the analysis, we considered three tasks: registration of pesticides, pesticide residue levels in food, and pesticide residue levels in environmental media. The registration of pesticides was conducted by the Ministry of Agriculture, Food, and Rural Affairs in Korea; the Directorate-General for Health and Food Safety in the European Commission (EC); and the US Environmental Protection Agency (USEPA) in the USA. The work regarding pesticide residue levels in food was conducted by the Ministry of Food and Drug Safety in Korea, the Directorate-General for the Health and Food Safety in the EC, and the USEPA and Food and Drug Administration in the USA. The work regarding pesticide residue levels in environmental media was conducted by the Ministry of Environment in Korea, the Directorate-General for Environment in the EC, and the USEPA in the USA. Therefore, Korea should review the extension of pesticide residue standards in the environmental media for strengthening the system of management of unregulated agricultural pesticides.

• Korean Journal of Soil Science and Fertilizer
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• v.11 no.4
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• pp.213-233
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• 1979

It is generally agreed that the country's population will grow up to the level of 52 million by the year of 2000 and that due the active growth of industry, urbanization and road constructions, sizable portion of existing arable lands will be utilized for other purposes than agriculture in near future. From 1966 to 1977, it was estimated that, the average annual conversion of arable lands to other uses, was 12,909 ha. If this trend persists, it is predicted that from 1978 to 1991 when the 6th Five Years Economic Development Plan will terminate, approximately 181,000 ha of arable lands will be converted for other uses again. On the other hand, it is certain that the increased population (39 million in 1981, 45 million in 1991, 52 million in 2001) and the changes in food pattern along with the enhancement of living standards will bring about the phenomenal increase in demands for not only the staple food but also the livestock products such as meat, milk and eggs, vegetables and fruits. These future increased demands for various foods, naturally mean the increased needs for the expansion of arable lands at the same time. It is predicted that, if more activities than present scale are not taken for the expansion of arable lands, the national food self sufficiency level will drop from 79% in 1977 down to 62% in 1991. To meet the increased food demands in future, there are several ways and means. These will include the increased land use intensity, elevation of unit area yield levels, minimization of conversion of arable lands to other uses and expansion of arable lands through the reclamations of idle hillside lands and tidal lands. Among these, the expansion of arable lands through reclamations of idle hillside lands and tidal lands are more positive measures to cope with the increased production of foods in future. The reclamation of hillside lands demands more attention because it needs more advanced technologies in agronomical and engineering aspects, larger scale fundings and integrated socioeconomic considerations. In agromical aspects, the thechniques for early improvement of chemical and physical properties of soils, proper soil conservation measures and rational cropping systems are of particular importance. As to the financial supports to encourage the farmings in hillside land, much bold fund inputs are essential for the construction of roads, installation of irrigation and drainage facilities, soil conservation mechanisms, which will ensure the stabilized farming with reasonable incomes in the newly reclaimed lands.