• Korean Journal of Organic Agriculture
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• v.22 no.1
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• pp.97-113
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• 2014

An actual proof experiment was carried out to establish the production of high quality organic rice at farm household in Gwangjin, Junnam, Korea 2011. Experimental plot was designed with conventional organic cultivation and manual organic cultivation in both Hopeongbyeo and Onnuri varities. Experimental field was consisted with suitable drainage loam soil, anryong series, and normal paddy field. Chemical characteristics of the soil were investigated from initial soil and soil after harvest in experimental sites. Seed disinfection was treated with hot water dipping method at $60^{\circ}C$ for 10 min. Rice transplanting was carried out at 17 June with 25 days seedling using machine transplanting. Golden apple snail was used to prevent weed growth as middle size (1.5~1.7 kg/10a) at one week after rice transplanting. Amount of applied fertilizer in experimental plot was supplied with organic fertilizer for the shortage after harvest of hairy vetch (1,100 kg/10a). Bordeaux mixture was used to control of sheath blight and neck blast disease in all experimental plot at 19 Aug. Application of chitin culture solution was treated in manual organic cultivation at 2 and 15 Aug. At late growth stage, incidence rate of neck blast was the highest level at Hopyeongbyeo in conventional organic cultivation. Incidence rate of sheath blight in both Hopyeongbyeo and Onnuri was higher in conventional organic cultivation than in manual organic cultivation. Incidence of rice leaf folder was the highest level at Onnuri in conventional organic cultivation. Yield index in manual organic cultivation was increased by 13% and 38% at Onnuri and Hopyeongbyeo, respectively, compared with conventional organic cultivation. Head rice percentage in both Hopyeongbyeo and Onnuri was slightly increased in manual organic cultivation. These results indicate that high quality production of rice organic cultivation could be depending on management of safe fertilization with nutrient content in soil.

• Korean Journal of Food Science and Technology
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• v.52 no.4
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• pp.317-324
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• 2020

In order to create the national food nutrient database, a total of 41 animal foods (ham, seafood, edible insects and eggs) were analyzed for their vitamin B₁₂ content and the applied immunoaffinity-HPLC was verified. Ham vitamin B₁₂ contents were 0.30-0.65 ㎍/100 g. Seafood showed relatively high vitamin B₁₂ level, where the values of fermented clam were the highest (26.80 ㎍/100 g) followed by fermented pollack roe. Vitamin B₁₂ was not detected in silkworm pupae and beetles, while relatively high levels were found in the two-spotted cricket imago (6.70 ㎍/100 g). Chicken and quail egg yolk had roughly 100- and 30-times higher vitamin B₁₂ levels as compared to their egg white. Vitamin B₁₂ contents in quail and chicken eggs were significantly enhanced by boiling (p<0.05). Results based on accuracy (97-102% recovery) and precision (<5% RSD) indicate that this study provides reliable vitamin B₁₂ information on animal foods consumed in Korea.

• Korean Journal of Ecology and Environment
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• v.33 no.4 s.92
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• pp.336-341
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• 2000

This study was conducted to clarify the habitat characteristics and distribution of seagrass. Zostera marina L. (Zosteraceae) in the brackish Hwajinpo Lake, Korea in June 1998 and July 2000. Z. marina beds were distributed along the sea-side cost of the lower lake mouth at 0.8 to 1.5m in death, and the seagrass bed area was about 3,200 m$^{2}$. Salinity, water temperature and pH were in the range of 8.0${\sim}$23.0$%_{o}$, 22.0${\sim}$23.7$^{\circ}C$ and 8.34${\sim}$8.62, respectively. Nutrient concentrations were generally now (TN: 24.34 ${\mu}$M, NH$_{4}$-N: 2.57 ${\mu}$M, NO$_{3}$-N: 0.56 ${\mu}$M, NO$_{2}$-N: 0.27 ${\mu}$M, TP: 2.08 ${\mu}$M, PO$_{4}$-P: 0.34 ${\mu}$M). Suspended particulate matters (SPM) concentration averaged 62.8 mg/l and particulate organic matter (POM) averaged 21.3 mg/l. Organic content of SPM averaged 33.9%. The beds substratum was composed of well-sorted, fine sand and its mean brain size was 3.13${\Phi}$. The Z. marina vegetation was almost submerged, and the morphological characteristics can be classified as steno-leaf phenotype by the shoot length, leaf width, and number of leaf vein. Shoot length and leaf width were 70.0${\sim}$126.5 cm and 5${\sim}$7 mm, respectively. Shoot densities ranged from 264 to 296/m$^{2}$, and the plants biomass was estimated at 332.6 to 373.0 g dw/m$^{2}$. Therefore, the habitats of Z. marina in Korea were recognized in a brackish lake, and morphological characteristics appeared to be variable.

• Korean Journal of Poultry Science
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• v.18 no.1
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• pp.9-31
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• 1991

The purpose of this study was to investigate the effects of dietary methionine and lysine levels on laying hen performance. The level of protein was fixed 15% during whole experiment period, but the levels of methionine and lysine were 0.30% and 0.58% (Low), 0.32% and 0.64% (Medium), 0.35% and 0 70% (High), respectively. Total 288 laying pullets of 22 weeks age were reared from January 28, 1989 to March 23, 1990 for 60weeks. The results obtained were summarized as follows : 1. The e99 Productions were highest in medium treatment in phase I (22~42weeks of age), phase II (42~62 weeks of age) and phase III (62~82weeks of age) and especially, there was significant difference among treatments during phase II (P＜0.05). 2. Egg weight was significantly increased as the levels of methionine and lysine were increased up to methionine and lysine were 0.32% and 0.64%, respectively(P＜0.01). 3. Daily egg mass was highest when the levels of methionine and lysine were 0.32% and 0.64%, respectively and there were significant differences among treatments during phase I and phase II (P＜0.01) 4. Daily feed intake was increased as the levels of methionine and lysine were increased, and there was significant difference among treatments during phase III (P＜0.05). 5. Feed efficiency was best in medium treatment in phase I and phase II (P＜0.01) 6, Viability was highest in medium treatment, but there was no significant difference among treatments. 7. Nutrient utilizability of experimental diets was not significantly different among treatments. 8. Eviscerated yield was highest and abdominal fat accumulation was lowest in medium treatment, but there was no significant difference among treatments. 9. Egg shell quality and chemical composition of egg content were not different among treatments. 10. The feed cost per kg egg mass was lowest in medium treatment and there were significant differences among treatments in phase I, phase II and whole egg laying period(P＜0.05)

• Journal of Bio-Environment Control
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• v.26 no.2
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• pp.100-107
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• 2017

This experiment was carried out to analyze the effects of substrate reuse on the growth and yield of summer paprika in cyclic hydroponics. The test group was divided into a new coco slab, one year reused coco slab two year reused coco slab based on 30% nutrient solution reuse, and was performed from April 18 to November 31, 2016 for 30 weeks. As a result, plant height of early growth was that the 2 year reused slab was longer than the new slab but the final growth period was 56.58 cm shorter. First group flower position was that reused slab was shorter by 2.92 cm than the new slab and the second group flower position was 0.31 cm long. The relative internode length of early growth, when the reused slab was used, the imbalance in the late growth stage was increased compared with the use of the new slab. The number of growth nodes in the 1 and 2 year reused slab was the smallest with 27.4 nodes. However, the number of harvested nodes did not show the difference in the test group, and the ratio of harvested that the 2 year reused slab was the highest at 26.8%. The ratio of unmarketable fruit tended to increase as the growth progressed. Fresh weight was 227.7g for new slab, 219.2g for 2 year reused slab and 21.2g for 1 year reused slab. The dry weight of the new slab increased with the reuse of the slab. It was 17.13g for new slab, 18.26g for 1 year reused, and 19.28g for 2 year reused. The average water content of the entire growth period was smaller as the slab was reused, and the 1 year reused slab was about 20g less than the 2 year reused slab. This trend was steadily occurring throughout the entire growing season. Especially, the reused slab for 1 year was less than 60g after 3 groups compared to other test groups. In conclusion, If will control seriously occurrence of unmarketable fruits by weakening after medium growth in summer-cultivated paprika in EC-based recycling hydroponic cultivation with reused cocopeat substrate, It is not what I have to worry that decrease of the yield and deterioration of the quality due to the change of physical and chemical properties of the slab and the pathogenic bacteria infection.

• Journal of Animal Science and Technology
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• v.48 no.3
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• pp.443-452
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• 2006

The four rice(Oryza sativa L.) lines, previously demonstrated to have vigorous herbage production at the vegetative growth stage, were investigated for their growth traits, dry matter yield and feed value using the twice-cutting system that 1st-cut is harvested at panicle formation stage and 2nd-cut at the yellow ripen stage. The twice-cutting system is regarded as an effective method in the production of forage rice by escaping lodging and insect damages caused by the overgrowth and typhoon around the heading stage.The feed value of the twice-cut rice plant of there lines were compared with the control of normal, cutting at the yellow ripen stage. The relative feed value(RFV), the total digestible nutrient(TDN) and the crude protein(CP) content of the twice-cut straw were higher the control in every lines. However, the dry matter yield (DMY), represented by the summed forage production of 1st and 2nd cut-rice plant, were lower the control, and the DMY of straws were increase but grains were decrease for twice-cutting system. In addition, TDN yield showed the similar tendency with DMY.Recently, as one of the breeding aims the researches for improving the digestibility of rice straw have been required. In this regard, twice-cutting system is recognized with the fact that it has the effect which raises the digestibility of the straw. Especially, the 2nd cut of IR73111-B-R-15-3-1 line was similar to the control at the TDN yield of straw, and would be used as a breeding material for product the roughage of good quality.

• Korean Journal of Poultry Science
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• v.35 no.2
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• pp.137-142
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• 2008

This study was conducted to investigate the effect of single or mixed supplementation of bacterial and fungal phytase using 45-wk-old 450 Hy-Line Brown laying hens housed in individual cages for 12-wk period. The birds were reallocated to have similar egg productivity by examining the egg production for one wk before starting the experiment. Two sources of phytase, bacterial (BP) and fungal (FP), were used either in single or mixture to determine the effects of these phytase. Five dietary treatments consisted of control (BP 0, FP 0), T1 (BP 300, FP 0), T2 (BP 300, FP 300), T3 (BP 300, FP 3000), and T4 (BP 0, FP 3000). The DPU was used for phytase activity in this experiment. The nonphytate phosphorus (NPP) content of control was 0.30%, and those of phytase treatments were set to 60% of the Control. Experimental diets were fed ad libitum throughout the experimental period. The lighting schedule of 17L7D was employed. The egg production was not different between control and bacterial phytase treatments, but the T4 showed significantly low productivity compared to control (P<0.05). No difference was found in average egg weight among all treatments. The daily egg mass did not show any statistical differences among all treatments: however, it was significantly low in T4 compared to ther control during the latter half of the experiment (P<0.05). No significant difference was found among treatments in terms of feed intake, feed conversion and egg quality. The digestibilities of dry matter, crude protein, and fat digestibility were similar regardless of the treatments. No significant trends were detected in Ca and P availability. In conclusion, the BP level of 300 DPU contributed to achieve 40% reduction of recommended nonphytate phosphorus addition. The synergistic effect of bacterial and fungal phytase was not confirmed.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.3 no.4
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• pp.234-248
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• 1998

Seven box cores from the disposal areas located in the southern part of the East Sea (Stations Band B') and in the offshore to the east of Pusan (Stations J and J'), and from their surrounding areas (Stations J2, J6 and H) were collected to investigate the effect of dumped wastes on the foraminiferal assemblages. The species diversity indices [S, H(S), E] of foraminifera and the total number of foraminifera show significant differences between the ocean waste disposal areas and their adjacent areas. Ocean waste disposal areas located in southern part of the East Sea (Stations Band B') show not only smaller number of foraminifera species but also lower values of coarse fraction content in the sediment and the number of benthic and planktonic foraminifera than the surrounding areas. Another ocean disposal area located offshore Pusan (Station J') contains abnormally greater number of planktonic (approximately 300 000 individuals/lO g dried sediment) and benthic (approximately 300, 000 individuals/10 g dried sediment) foraminifera compared to those of the adjacent areas. The waste dumped at Station J' probably acts as a nutrient causing the greater number of foraminifera. Station J shows low species diversity indices [S, H(S)]. The number of benthic foraminifera decreases from the surface to the downcore at Station J, which indicates that Station J is under stress. However, Stations J', J2 and J6 are under stable conditions as evidenced by the greater species diversity indices [S, H(S)] compared to other stations. No foraminifera were found with biological disease or abnormal chambers, which commonly occur in extremely stressed environment, in both the ocean disposal and adjacent areas. The organic matter decay of the wastes dumped in the study areas has not made the bottom water corrosive.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.1
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• pp.50-56
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• 2015

Italian ryegrass is generally cultivated by a winter forage in a paddy field, the harvest season overlaps with rice transplantion in some cases. In addition, farmers can miss the optimal seedtime for Italian ryegrass because of the rainy season. Therefore, this research was conducted between October 2012 and June 2013 in Kwangjin, Korea to examine the effect of spring-seeding on the yields and quality of Italian ryegrass for the determination of an alternative if the optimal seedtime is missed. This trial consists of four different seeding dates (15 February, 25 February, 5 March, and 15 March) and three varieties (Kowinmaster, Kowinearly, and Green farm). The Italian ryegrass varieties "Kowinmaster," "Kowinearly," and "Green farm" were sown on February 15. The heading date of each variety showed from May 12 to May 9 and interval time of five days but the Treatment of March 15 planting date showed three days interval. The Kowinmaster variety, planted on February 15, was 93.0 cm taller on March 15 with a height of 105.7 cm. The Kowinearly and Green farm varieties planted on February 15 were of a similar height on February 25 and received a poor lodging score when planted quickly. The dry matter (DM) yield of the Kowinearly planted on February 15 was high but that of Green farm was low at 6,609 kg/ha and a difference was not shown between the varieties. The DM yield was different for those varieties planted on February 15 and March 15 (P<0.05). The crude protein content (CPC) of those varieties planted on February 15 showed an average of 8.8%, while those that were planted on March 15 showed an average that was about 2.3% higher at 11.1%; furthermore, the latter also showed lower acid detergent fiber (ADF) and total digestible nutrient (TDN) contents, by 2.1% and 1.5%, respectively. The relative feed value was about 5.9% higher, depending on the seeding date, as well as being slower and showing less difference between the varieties. According to this study, Italian ryegrass planted in a paddy field of the southern region of Korea on February 25 will produce a high-quantity yield with nutritive value.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.1
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• pp.45-51
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• 2013

This study was performed on two groups (10 cows) for primiparous Holstein lactating cows (av. 98 days in milk : DIM) which were divided into low forage diet (LF) and high forage diet (HF) groups based on forage : concentrate ratio (F : C ratio). The F : C ratios of LF and HF groups were 37:63 and 62:38, respectively. Concentrate intake was significantly higher in the LF group than the HF group whereas the HF group showed higher forage intake (12.9 kg) compared to the LF group (7.4 kg) (p<0.05). No significant difference was observed in total feed intake between the HF (20.9 kg) and LF (19.4 kg) group (p>0.05), but the HF group tended to be higher. CP, TDN and NEL intake showed no significant difference between the two groups (p>0.05). Though, there was no significant difference on actual milk between the two groups (26 vs. 23.9 kg/d, p>0.05), the LF group tended to be higher. 4% FCMs of LF and HF groups were 22.8 and 22.3 kg/d, respectively, and showed no significant difference (p>0.05). The HF group was higher in fat content and lower in MUN. C14:0, C16:0 and C16:1n7 of milk fatty acid were significantly higher in the HF group (p<0.05), but there were no differences in other milk fatty acids between the two groups. As a result, increasing high quality forage such as BIRG silage and hay in the diet will not only fulfill nutrient requirements but also reduce milk production.