• Journal of Animal Science and Technology
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• v.47 no.4
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• pp.583-592
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• 2005

This experiment was conducted to determine the effects of dietary copper levels on performance, carcass characteristics, and economical analysis in Hanwoo steers. Fifteen Hanwoo steers weighing about 300kg were randomly allotted into one of three treatments. The three treatments consisted of Control(7mg Cu/kg feed), TI(12mg Cu/kg feed) and TII(17mg Cu/kg feed). Copper was formulated with concentrate from copper sulfate($CuSO_4$) and animals were fed the diets supplemented with copper from 300kg untill about 630 kg of body weight. Dietary copper levels did not affect daily weight gain, feed intake and feed efficiency during the whole feeding period. Dressing percentage, rib eye area and backfat thickness were not different between animals fed the diets supplemented with copper. Animals fed the diets supplemented with copper received the same B grade in yield grade. Animals fed the diets supplemented with copper received same marbling score. Beef color, fat color, texture and maturity were not affected by Cu supplementation in diet. Animals received the same first grade between treatments in quality grade. Animals fed the diet supplemented with 12mg of copper per kg diet was higher in profit by 13.3% than animals fed the control diet. According to these results, it may be concluded that performance, yield and quality grade were not affected by the Cu levels of 7 to 17mg per kg feed but crude income was enhanced when Hanwoo steers were fed the diet containing 12mg Cu/kg feed.

• The Korean Journal of Petroleum Geology
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• v.5 no.1_2 s.6
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• pp.48-58
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• 1997

Core samples from the B, E, F, H wells in the Tertiary Pohang Basin were analysed for total organic carbon (TOC) content and subject to Rock-Eval pyrolysis in order to assess petroleum geochemical characteristics of organic matter. Following geochemical screening, we selected samples from each well for the study of bitumen and kerogens such as optical observation, infra-red spectroscopy and biomarker analyses. Sediments of the Tertiary Yonil Group contain total organic carbon ranging from $0.55{\%} to 3.74{\%}$ with S1+S2 values higher than 2mgHC/g Rock in B, E and F wells, which indicates fair hydrocarbon generation potential. Most organic matter in the B, E, F wells is compared to type II based on the Rock-Eval pyrolysis, infra-red spectroscopy and optical observation. However, organic matter in the H well is compared to type III because the well is located at the margin of the basin where the preservation of terrestrial material is dominant. Geochemical analyses show that organic matter in the Yonil Group is thermally immature although thermal maturity slightly increases with depth. Maturity levels of the extracted kerogens are similar to those of bulk samples ($Tmax<435^{\circ}C$. Petroleum geochemical charateristics of the sediments in the Tertairy Yonil Group is fair in terms of the organic richness and hydrocarbon genetic potential, but organic matter is thermally immature due to the shallow burial depth. Optical observation of the kerogens and biomarker analysis show that organic matter in the Yonil Group is both marine and terrestrial origin, although it was deposited in marine environment. Pristane/phytane ratio suggests rather anoxic depositional environment. Transitional characteristics of organic matter indicate that the marine Yonil Group was deposited near the terrestrial environments. Input of terrestrial organic matter is more prevalent in the samples recovered from the lowermost horizon in the wells due to the terrestrial environment at the time of basin formation.

• Korean Journal of Veterinary Research
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• v.14 no.1
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• pp.115-133
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• 1974

Although considerable research has been done on the changes associated with age in the blood picture of domestic and laboratory animals, little work has been made of the changes occurring at different age in the blood picture of goats. And a comprehensive survey of the bood picture of Korean native goats has not been made. The object of the present investigation was to suggest standards for the blood picture of Korean native goats at frequent intervals from birth to maturity. The goats were kept under average farming conditions in this country. Observations were made at the following ages: at birth; 2,4 and 7 days; 2, 3, 4, 5, 6, 7, 8 and 9 weeks; 2.5, 3,6 and 12 months. Blood samples were drawn from the jugular vein. It was taken between 8 and 9 a.m. except those for the at-birth period. Erythrocyte and leukocyte enumerations and, determinations of hemoglobin in blood and hematocrit value were made in the usual manner. Reticulocytes were enumerated per 1,000 erythrocytes in blood smears stained with briIliant cresyl blue and counterstained with Wright's stain. Erythrocytes counts declined from $8.7{\times}10^8/mm^3$ at birth to a low of 7.0 at 4 days of age. These values increased to 11.5 at 5 weeks and reached a maximum of 14.0 at 3 months of age; it then fell to 11.5 at 12 months of age. Concentrations of hemoglobin in blood and hematocrit values were not related to the changes of erythrocyte counts. The values at birth were higher than at any other period during the first year of life. These fell from highs of 12.3 g/100 ml and 38.0 ml/100 ml to lows of 9.2 and 29 at 4 weeks for concentration of hemoglobin in blood and hematocrit value, respectively. There was a common pattern for the hematocrit value and hemoglobin in blood which showed three phases-a fall during the first month, a rise to the third month, and a fall to the mature level at 12 months of age. Mean corpuscular volume and mean corpuscular hemoglobin showed a common pattern. The values were $44.2{\mu}m^3$ and 14.2 pg at birth and fell, at first slowly and then rapidly, to reach adult levels of 24.1 and 7.9 at 6 weeks of age for mean corpuscular volume and mean corpuscular hemoglobin, respectively. Mean corpuscular hemoglobin concentration was little affected by age. Reticulocyte was observed from birth to 4 weeks of age. Percentage of reticulocyte decreased from 0.85% at birth to 0.06% at 4 weeks of age. Total leucocyte counts increased from $5.64{\times}10^3/mm^3$ at birth to a maximum of 13.4 at 3 months; it then fell to 11.5 at 12 months of age. In differential counts myelocyte, juvenile and band form decreased with advancing age. No myelocyte and juvenile were seen after the age of 7 and 9 weeks, respectively, and band forms were rare after the age of 3 months. Percentage of mature neutrophil showed a quick decline from 52.5% at birth to reach a minimum level (34.5%) at 3 months of age; it then rose to 38% at 12 months of age. Percentage of lymphocyte increased from 39.2% at birth to maximum of 59% at 3 month of age; it then fell to 54.9% at 12 months of age. Percentage of monocyte was not affected with advance of age. Percentage of eosinophil and basophil were increased with advance of age to reach a maximum at 2 to 3 month of age. It then fell to adult level at 12 month of age.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.2
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• pp.177-183
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• 1989

Lower leaves of aromatic tobacco are also much lower in Quality than upper leaves. So feasibility test of no harvesting and curing of lower leaves was conducted under high planting density and high nitrogen conditions with conventional cultural system. Effect of harvesting time on yield and Quality were investigated under 2 nitrogen levels. Among harvesting methods of conventional harvest with priming under high planting density, no-harvest of first priming, removal of lower leaves which relevant to first prime stalk before maturity, no-harvest of first and second priming. no-harvesting or pruning of first prime stalk before maturity was best in yield, price and in crude income. The shortor the harvest period became, the lower the yield, price and contents of reducing sugar and nicotine became, but reverse in this trends with total nitrogen and protein nitrogen. So 6 or 8 days interval of harvest is most recommendable.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.1
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• pp.57-66
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• 2013

The purpose of this study was to investigate the effects of shifts in sowing time on the ecological responses, growth and yields of major soybean cultivars in a southern region of South Korea. Experiments were carried out in Naju, Jeonnam Province (latitude $35^{\circ}$ 04'N, longitude $126^{\circ}$ 54'E) for three years from 2008 to 2010. The test cultivars included Saeol-kong and Tawon-kong of the summer type, Taekwang-kong and Pungsannamul-kong, and Cheongja3 of the autumn type. Sowing took place on May 15 and 30, June 15 and 30, and July 15 of each year. Of the summer type soybean cultivars, Saeol-kong showed a smaller curtailment in days from sowing to flowering, days from flowering to maturity, and days from sowing to maturity according to sowing time postponement than Tawon-kong. Of the autumn type soybean cultivars, Taekwang-kong exhibited a lower photoperiodic response in reproductive growth period than Pungsannamul-kong and Cheongja3, both of which recorded higher level photoperiodic responses in vegetative growth stages and reproductive growth periods than other test cultivars, with the former exhibiting higher levels than the latter. Most of the test cultivars tended to decrease in stem length, node numbers of the main stem, and stem diameter according to postponed sowing time, but there were no significant differences in stem length and node numbers of the main stem of the Saeol-kong cultivar. Differences in sowing times did not affect the first setting pod node order of Saeol-kong and Tawon-kong summer type cultivars of internode lengths of all of the test cultivars. All of the test cultivars tended to show decreases in pod number per plant due to postponement of sowing time except for the Saeol-kong cultivar. The variation was more prominent in small grain cultivars such as Tawon-kong and Pungsannamul-kong with the latter autumn type cultivar showing especially large variation. Yields were the greatest for the Tawon-kong, Taekwang-kong, and Pungsannamul-kong cultivars sown on May 30 and Cheongja3 sown on May 30 and June 15. There were no significant differences in the yields of Saeol-kong for different sowing times from May 30 to July 15, with the yields lowest for the batch sown on May 15.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.5
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• pp.747-754
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• 2005

Nutritional regulation of gene expression associated with growth and feeding behavior in avian species can become an important technique to improve poultry production according to the supply of nutrients in the diet. Insulin-like growth factor-I (IGF-I) found in chickens has been characterized to be a 70 amino acid polypeptide and plays an important role in growth and metabolism. Although it is been well known that IGF-I is highly associated with embryonic development and post-hatching growth, changes in the distribution of IGF-I gene expression throughout early- to late-embryogenesis have not been studied so far. We revealed that the developmental pattern of IGF-I gene expression during embryogenesis differed among various tissues. No bands of IGF-I mRNA were detected in embryonic liver at 7 days of incubation, and thereafter the amount of hepatic IGF-I mRNA was increased from 14 to 20 days of incubation. In eyes, a peak in IGF-I mRNA levels occurred at mid-embryogenesis, but by contrast, IGF-I mRNA was barely detectable in the heart throughout all incubation periods. In the muscle, no significant difference in IGF-I gene expression was observed during different stages of embryogenesis. After hatching, hepatic IGF-I gene expression as well as plasma IGF-I concentration increases rapidly with age, reaches a peak before sexual maturity, and then declines. The IGF-I gene expression is very sensitive to changes in nutritional conditions. Food-restriction and fasting decreased hepatic IGF-I gene expression and refeeding restored IGF-I gene expression to the level of fed chickens. Dietary protein is also a very strong factor in changing hepatic IGF-I gene expression. Refeeding with dietary protein alone successfully restored hepatic IGF-I gene expression of fasted chickens to the level of fed controls. In most circumstances, IGF-I makes a complex with specific high-affinity IGF-binding proteins (IGFBPs). So far, four different IGFBPs have been identified in avian species and the major IGFBP in chicken plasma has been reported to be IGFBP-2. We studied the relationship between nutritional status and IGFBP-2 gene expression in various tissues of young chickens. In the liver of fed chickens, almost no IGFBP-2 mRNA was detected. However, fasting markedly increased hepatic IGFBP-2 gene expression, and the level was reduced after refeeding. In the gizzard of well-fed young chickens, IGFBP-2 gene expression was detected and fasting significantly elevated gizzard IGFBP-2 mRNA levels to about double that of fed controls. After refeeding, gizzard IGFBP-2 gene expression decreased similar to hepatic IGFBP-2 gene expression. In the brain, IGFBP-2 mRNA was observed in fed chickens and had significantly decreased by fasting. In the kidney, IGFBP-2 gene expression was observed but not influenced by fasting and refeeding. Recently, we have demonstrated in vivo that gizzard and hepatic IGFBP-2 gene expression in fasted chickens was rapidly reduced by intravenous administration of insulin, as indicated that in young chickens the reduction in gizzard and hepatic IGFBP-2 gene expression in vivo stimulated by malnutrition may be, in part, regulated by means of the increase in plasma insulin concentration via an insulin-response element. The influence of dietary protein source (isolated soybean protein vs. casein) and the supplementation of essential amino acids on gizzard IGFBP-2 gene expression was examined. In both soybean protein and casein diet groups, the deficiency of essential amino acids stimulated chickens to increase gizzard IGFBP-2 gene expression. Although amino acid supplementation of a soybean protein diet significantly decreased gizzard IGFBP-2 mRNA levels, a similar reduction was not observed in chickens fed a casein diet supplemented with amino acids. This overview of nutritional regulation of IGF-I and IGFBP-2 gene expression in young chickens would serve for the establishment of the supply of nutrients to diets to improve poultry production.

• Korean Journal of Agricultural Science
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• v.45 no.1
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• pp.19-27
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• 2018

To study the effect of natural anti-microbial chemicals on the growth and quality of chili peppers, chitosan ($100mg/L^{-1}$), stevia ($250mg/L^{-1}$), and the mixture of both chemicals at the same concentration were sprayed after planting at 1-week interval throughout the experimental period. Plant height was measured twice after the $3^{rd}$ and $4^{th}$ applications. Plant height was numerically reduced in all chemical treatments compared to that of untreated control; however, there was no statistical difference between treatments. The fruit quality was examined at commercial maturity, and only minor differences were found in fruit color, length, and dry matter content between the treatments. Although a statistical difference was not present for soluble sugars levels, total phenolics, and capsaicin contents, yield in all chemical treatments significantly increased compared to untreated control. The effect on yield increase was greater at the late harvest season regardless of treatments. Total yield of 4 harvests was higher for the chitosan treatment than other treatments. During the experiment, the entire experimental field was waterlogged for 1 day due to sudden heavy rainfall, which resulted in the occurrence of bacterial browning disease in all treatments. The rate of disease occurrence and the degree of severity, however, were much lower in the chitosan treatment. In conclusion, the potential of chitosan as an alternative antimicrobial agent was confirmed in chili peppers in this study. Further research is required on stevia as an alternative chemical for disease control in chili peppers.

• Korean Journal of Environmental Biology
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• v.33 no.2
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• pp.248-255
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• 2015

Induction of regeneration and maturation of the free-living gametophytes of Saccharina japonica was studied at four temperatures (5, 10, 15 and $20^{\circ}C$), four levels of irradiance (5, 10, 20 and $40{\mu}mol\;m^{-2}\;s^{-1}$) and three photoperiods (14 : 10, 12 : 12 and 10 : 14 h L : D). Female gametophyte fragments were maintained in active regeneration without reaching sexual maturity under conditions of $15^{\circ}C$, $20{\mu}mol\;m^{-2}\;s^{-1}$, 10 : 14 h (L : D), whereas the conditions for male gametophytes were slightly different at $15^{\circ}C$, $5{\mu}mol\;m^{-2}\;s^{-1}$, 14 : 10 h (L : D). The sexual maturation of female and male gametophytes took place under $5^{\circ}C$, $20{\sim}40{\mu}mol\;m^{-2}\;s^{-1}$, 10 : 14 h (L : D) and $15^{\circ}C$, $40{\mu}mol\;m^{-2}\;s^{-1}$, 10 : 14 h (L : D), respectively. These results provide basic information for controlling the regenerationand maturation of free-living gametophytes for strain improvement and cross breeding of S. japonica.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.3
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• pp.338-342
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• 2015

There has been known C3G (Cyanidin-3-Glucoside), D3G (Delphinidin-3-Glucoside), and Pt3G (Petunidin-3-Glucoside) were main anthocyanin pigments in black-seeded soybean. Anthocyanin contents of total 1,032 black-seeded soybean germplasms were analyzed by HPLC. Average of total anthocyanin content was 11.67 mg/g on the all materials ranged from 0.54 to 23.45 mg/g. Mean value of C3G, D3G, and Pt3G contents in all black-seeded soybeans were 8.81, 1.78 and 0.79 mg/g, respectively. Environmental conditions influenced anthocyanin contents during seed development. Delayed flowering, especially of later maturing germplasms, has been showed to result in increased anthocyanin content. So, prolonged maturation period germplasm is generally higher than that of shorten genotypes. It may be concluded that the higher levels of anthocyanin content was associated with the late dates of harvest maturity. Also larger seeds showed high anthocyanin contents than smaller. That inclination is similar in C3G's occasion because C3G content contribute highly to total anthocyanin content than other pigments.

• Journal of The Korean Society of Grassland and Forage Science
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• v.5 no.2
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• pp.111-115
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• 1985

This experiment was conducted to investigate the effects of maturity and intake on digestibility of grass hay harvested at different dates. Hay was prepared from first-growth forage which cutting dates were: 4 June (vegetative, called early-cut) 30 June (heading, called late-cut). The grass hay fed to wethers at restricted and ad libitum levels of intake. The results obtained are summarized as follows: 1. As delay in cutting date, contents of crude protein and crude fat decreased, while fibre and lignin increased. 2. On ad libitum feeding of early-cut and late-cut hay, the DM intake were $82g/W_{kg}^{0.75}\;and\;68g/W_{kg}^{0.75}$ respectively. 3. There was no significant difference in dry matter digestibility of early-cut hay between restricted and ad libitum feeding, but dry matter digestibility was decreased markedly in ad libitum feeding when leaves fecal condition out of account. Digestibility of crude protein, organic matter and fibre contained in early-cut hay were tended to decrease slightly in ad libitum when compared with restricted feeding, but were not significantly. 4. Digestibilities decreased significantly with increase of intake in late-cut except for crude protein (P<0.05 or P<0.01). 5. In the comparison of digestibility for all composition, early-cut hay was higher (P<0.01) than late-cut hay.