• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.5
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• pp.794-803
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• 1997

Long line suspended culture of oysters has been started commercially in Hansan-Koje Bay since 1969. However, its Annual production has been decreased and culturing periods extended in recent years. So, we investigated environmental parameters and food organisms to identity the causes of poor fatness of oysters in Hansan-Koje Bay from February to November, 1994. As the result, the Water quality of Hansan-Koje Bay was found to be good for culture. For example, the mean concentration of COD was $1.35mg/\ell$, phosphate phosphorus was $0.30{\mu}g-at/\ell$ and dissolved inorganic nitrogen was $4.68{\mu}g-at/\ell$. However, the Hwado island and the inner part of the Hansan-Koje Bay were found to be eutrophicated due to various contaminants transported by land-based activities. But in the central pan of the Hansan-Koje Bay where the oyster farms Have been developed densely, the level of nutrient concentration was very low. During the study period, the dominant species of phytoplankton was Chaetoceros spp. with the percentage of $72.6\%\~87.8\%$ and the mean values of Chlorophyll-a concentration and phytoplankton standing crops were $2.05mg/m^3\;and\;188ind./m\ell$, respectively. The distribution of these parameters also showed similar trends those of nutrients. Especially, chlorophyll-a contents was very low with the concentration of below $0.5mg/m^3$ at central part of the Bay, Juklimpo. The fatness of oysters and the eutrophic index in this area were $18.1\%$ and 0.54, respectively. These values were lower than those of other culturing farms in the southern coastal areas in Korea. Therefore, we estimated that the insufficient food supply due to the low level of nutritional status was the major factors affecting the poor fatness of the Pacific oysters in Hansan-Koje Bay.

• Journal of Animal Science and Technology
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• v.53 no.1
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• pp.29-34
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• 2011

Using the materials collected from nine farms in a three-way cross system to produce commercial pigs produced from F1 sows (Landrace $\times$ Large White) $\times$ Duroc, the power of individual discrimination and parentage of the 13 microsatellite (MS) marker set that has been suggested for individual/brand identification (traceability) was empirically tested. Initially, genotypes of the parental population ($F_1$ sows and Duroc), and commercial pigs were determined and the genotype frequency and polymorphic index were estimated using the Cervus 2.0 program. The probability of identity among genotypes of random individuals, that random half sibs and that of full sib individuals, based on the genotypes from 91 $F_1$ sows and Duroc were expected to be $4.94{\times}10^{-34}$, $8.16{\times}10^{-23}$ and $2.01{\times}10^{-08}$, respectively, using the API-CALC version 1.0 program. When commercial pigs were included, the estimates increased to $3.74{\times}10^{-35}$, $5.48{\times}10^{-25}$ and $2.96{\times}10^{-11}$, respectively. For the empirical verification of the estimated powers of individual discrimination and parentage, the parentage test was performed for 452 commercial pigs using PAPA version 2.0, and individuals with the same genotype were investigated using the Cervus version 2.0 program. Parents for all commercial pigs were successfully estimated and no identical individual was identified in the pedigree. Although the individual discriminating power was not fully verified because of the lack of individuals corresponding with the theoretical power, the 100% efficiency of parentage test was clearly confirmed. Therefore, we believe that the 13 MS marker set in conjunction with management record/information for the pig production kept in a farm/brand should be useful in the pork traceability in a brand unit.

• Korean Journal of Poultry Science
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• v.34 no.1
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• pp.43-52
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• 2007

Experiments were conducted to investigate the effects of dietary botanicals (herbs and plant extracts) on the performance, nutrient metabolizability, small intestinal microflora, IgG level and blood parameters in broiler chickens. In Exp. 1, 1,000 (500 each sex) broiler chicks($Ross^{(R)}$) were divided into 20 groups of 50 chickens each(25 birds each sex). Four groups were assigned to each of five dietary treatments:control and diets containing antibiotics($Avillamix^{(R)}$, avillamycin-premix), Herb M(Herb $mix^{(R)}$), Plant extract B(BIOSTRONG $510^{(R)}$) and Plant extract A($APEX^{(R)}$). In Exp. 2, 240(120 each sex) broiler chicks($Ross^{(R)}$) were devided into six treatment groups:control and diets containing antibiotics($Avillamix^{(R)}$, avillamycin-premix), Plant extract D($Digestarom^{(R)}$), Plant extract P($Phellozyme^{(R)}$), Plant extract G($Galicin^{(R)}$) and Plant extract C(CRINA $POULTRY^{(R)}$). Each treatment consisted of four replicates of 10 birds each. In both experiments, birds had free access to diets and water for 5 wk on floor pens(Exp. 1) and cages(Exp. 2). In Exp.1, production index of groups fed diets supplemented with herbs and plant extracts was slightly higher than the control and those fed Herb M was highest. In Exp. 2, groups fed diets supplemented with herbs and plant extracts consumed more feed than the control during the period between 4 and 5 wk(P<0.05). Feed conversion(feed/gain) was lower in antibiotics group than other groups. The values of RBC, Hb and HCT were higher(P<0.05) in chicken fed diets supplemented with the additives than in the control in Exp. 1. BA value was lower(P<0.05) in groups fed diets supplemented with the additives than in the control in Exp. 2. Serum IgG were higher(P<0.05) in groups fed diets supplemented with the additives than in the control in both experiments. The cfu of intestinal microflora and metabolizability of nutrients were not significantly different among treatments in both experiments. It was concluded that the botanical supplements can be used as an alternative to antibiotics in broiler diets.

• Korean Journal of Poultry Science
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• v.34 no.1
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• pp.9-14
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• 2007

This study was conducted to investigate the effects of coastal mud-flat bacteria origin protease supplementation on laying performance, nutrient digestibility and total protein concentration of serum in laying hens. A total of 252 laying hens were randomly allocated into three treatments with seven replications for eight weeks. Dietary treatments included 1) CON (basal diet), 2) PRO1 (basal diet + 0.05% protease) and 3) PRO2 (basal diet + 0.1% protease). During the entire experimental period, hen-day egg production was not affected by treatments (P>0.05). Difference of yolk height was increased in PRO1 treatment compared with CON treatment (P<0.05). Difference of egg weight was increased in PRO2 treatment compared with CON and PRO1 treatments (P<0.05). Shell quality, yolk color unit, haugh unit and egg yolk index were not affected by treatments (P>0.05). DM digestibility was improved in CON and PRO2 treatments compared with PRO1 treatment (P<0.05). N digestibility was improved in PRO2 treatment compared with CON treatment (P<0.05). Total protein concentration in serum were not affected by treatments (P>0.05). In conclusion, mud flat bacteria origin protease was effective for improving egg weight, yolk height and nutrient digestibility in laying hens.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.4
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• pp.264-272
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• 2013

Climate changes have caused not only changes in the frequency and intensity of extreme climate events, but also temperature and precipitation. The damages on agricultural production system will be increased by heavy rainfall and snow. In this study we assessed vulnerability of crop cultivation facility and animal husbandry facility by heavy rain in 232 agricultural districts. The climate data of 2000 years were used for vulnerability analysis on present status and the data derived from A1B scenario were used for the assessment in the years of 2020, 2050 and 2100, respectively. Vulnerability of local districts was evaluated by three indices such as climate exposure, sensitivity and adaptive capacity, and each index was determined from selected alternative variables. Collected data were normalized and then multiplied by weight value that was elicited in delphi investigation. Jeonla-do and Gangwon-do showed higher climate exposures than the other provinces. The higher sensitivity to abnormal weather was observed from the regions that have large-scale cultivation facility complex compared to the other regions and vulnerability to abnormal weather also was higher at these provinces. In the projected estimation based on the SRES A1B, the vulnerability of controlled agricultural facility in Korea totally increased, especially was dramatic between 2000's and 2020 year.

• Journal of Embryo Transfer
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• v.20 no.3
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• pp.255-269
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• 2005

This study was aimed to investigate genetic relationships, variables, and correlations between economic traits and metabolic materials in serum components according to bleeding periods and breeding locations for the castrated and not castrated Hanwoo cattle at National Livestock Research Institute. Analysis of variance for serum hormones and metabolic materials showed significant differences by breeding locations except for testosterone and globulin. Statistical differences for serum components were detected by birth year except for cortisol, total protein, globulin and creatinine, and by castration except for total protein and BUN. All the serum components were tended to have sire effects except for testosterone resulting in some degree of additive gene actions. Breeding locations showed statistical significances for carcass weight and back fat thickness, but not in carcass rate, KPH, live weight and transportation weight loss. Effects of breeding locations and castration were significant for all weight measurement periods except for 9 month and 6 month, respectively. A significant sire effect was observed in all weight measurements. Least squared means for concentration of serum components by breeding year, season and castration were not significant. High concentration of cortisol, creatinine and triglyceride and low concentration of IGF-1 and glucose were detected in castrated cattle. Concentration of testosterone with castrated cattle was $5.2\%$ corresponding to non castrated cattle. Estimation of heritabilities of serum components using a sire model with restricted maximum likelihood were ranged 0.07 to 0.58. High heritabilities were estimated for total protein, albumin, globulin, cortisol, creatinine and BUN were 0.53, 0.54, 0.42, 0.45, 0.58 and 0.54, respectively. Low heritabilities were estimated fur calcium, testosterone and IGF-1 for 0.07, 0.15 and 0.12, respectively. Heritabilities for carcass weight, back fat thickness, meat yield index, KPH, and IMF were estimated as 0.39, 0.45, 0.30 0.13, and 0.93. Heritabilities of weights on 18, 12, 9, 6, and 24 month were estimated as 0.78, 0.76, 0.62, 0.58 and 0.58. Estimated heritabilities for average daily gain on 6${\~}$2, 12${\~}$18, and 18${\~}$24 month were 0.80, 0.75 and 0.19, respectively.

• Korean Journal of Organic Agriculture
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• v.17 no.1
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• pp.111-125
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• 2009

Pitamin is a component of pine bark extract that exhibits antimicrobial activity and a variety of physiological effects. This study was earned out to investigate the effects of dietary pitamin as an organic livestock feed additive in broiler chickens. A 35 day trial was conducted to determine the influence of dietary premix containing 5% pitamin; investigated parameters included blood lipids, growth performance, quality characteristics of carcasses, and changes of caecal microbials in broiler chickens. Chickens were randomly divided into groups that were untreated (control), treated conventionally with antibiotics in the absence of premix, received 0.1 % or 0.2% premix containing 5% pitamin. Plasma lipids were lower in groups fed diets with pitamin premix (p<0.05). The body weight gain from broiler chickens fed with the diet containing 0.1% pitamin premix and antibiotics was similar, and was significantly higher than that of the other groups (p<0.05). The weight of breast muscle and thigh meat of carcasses was similar, and was higher than that of the control group (p<0.05). Abdominal fat and thymus index from chickens receiving either pitamin-supplemented premix was significantly lower and increased, respectively, that of the antibiotic and control groups (both p<0.05). The chickens on the pitamin premix-supplemented diets evidenced significantly higher caecal levels of Bifidobacterium species as compared with the chickens on the control diet (p<0.05). These results suggest that feeding a diet supplemented with a 0.1% premix containing 5.0% pitamin for 35 days maintains the production of broiler chickens at a level comparable to that obtained from the use of antibiotics.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.3
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• pp.215-231
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• 2020

Forest landscape models (FLMs) can be used to investigate the complex interactions of various ecological processes and patterns, which makes them useful tools to evaluate how environmental and anthropogenic variables can influence forest ecosystems. However, due to the large spatio-temporal scales in FLMs studies, parameterization and validation can be extremely challenging when applying to new study areas. To address this issue, we focused on the parameterization and application of a spatially explicit forest landscape model, LANDIS-II, to Mt. Gyebang, South Korea, with the use of the National Forest Inventory (NFI) and long-term ecological research (LTER) site data. In this study, we present the followings for the biomass succession extension of LANDIS-II: 1) species-specific and spatial parameters estimation for the biomass succession extension of LANDIS-II, 2) calibration, and 3) application and validation for Mt. Gyebang. For the biomass succession extension, we selected 14 tree species, and parameterized ecoregion map, initial community map, species growth characteristics. We produced ecoregion map using elevation, aspect, and topographic wetness index based on digital elevation model. Initial community map was produced based on NFI and sub-alpine survey data. Tree species growth parameters, such as aboveground net primary production and maximum aboveground biomass, were estimated from PnET-II model based on species physiological factors and environmental variables. Literature data were used to estimate species physiological factors, such as FolN, SLWmax, HalfSat, growing temperature, and shade tolerance. For calibration and validation purposes, we compared species-specific aboveground biomass of model outputs and NFI and sub-alpine survey data and calculated coefficient of determination (R²) and root mean square error (RMSE). The final model performed very well, with 0. 98 R² and 8. 9 RMSE. This study can serve as a foundation for the use of FLMs to other applications such as comparing alternative forest management scenarios and natural disturbance effects.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.2
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• pp.201-207
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• 1987

This experiment was conducted to identify the superior corn hybrids for silage production and to determine the combining ability of their parental inbred lines. A 7-entry diallel cross was evaluated for grain and stover yields, and agronomic characters under 3 different seasons. Hybrids Hi34 x Tx601, Hi26 x Hi34, and Hi29 x Hi34 showed high total dry matter yields. In general, late maturing hybrids had higher grain and silage yields than early maturing hybrids. Leaf area index was correlated with grain and stover yields. Rust rating was negatively correlated with yields and all characters, indicating that rust (Puccinia sorghi) was one of the major factors affecting yields. Diallel analysis showed that inbred Hi34 which was late in maturity and resistant to rust was the best combiner for both grain and silage yields. General combining ability (GCA) and specific com-bining ability (SCA) effects for yields and other characters were significant, suggesting that both additive and non-additive gene effects are involved for those characters. Ratio of GCA/SCA mean squares showed that GCA effects were more important than SCA effects for yields and other characters. GCA x season and SCA x season interactions were significant for grain and stover yields, revealing that gene effects were not stable for those yields under dissimilar environments.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.3
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• pp.217-226
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• 2015

To investigate the distributions of BVOCs (Biogenic Volatile Organic Compounds) from mountain near mega city and their role in forest atmospheric, BVOCs and their oxidized species were measured at a 41 m tower in Mt. Taehwa during May, June and August 2013. A proton transfer reaction-mass spectrometer (PTR-MS) was used to quantify isoprene and monoterpenes. In conjunction with BVOCs, $O_3$, meteorological parameters, PAR (Photosynthetically Active Radiation) and LAI (Leaf Area Index) were measured. The average concentrations of isoprene and monoterpenes were 0.71 ppbv and 0.17 ppbv, respectively. BVOCs showed higher concentrations in the early summer (June) compared to the late summer (August). Isoprene started increasing at 2 PM and reached the maximum concentration around 5 PM. In contrast, monoterpenes concentrations began to increase 4 PM and stayed high at night. The $O_3$ maximum was generally found at 3 PM and remained high until 5 PM or later, which was concurrent with the enhancement of $O_3$. The concentrations of BVOCs were higher below canopy (18 m) than above canopy, which indicated these species were produced by trees. At night, monoterpenes concentrations were negatively correlated with these of $O_3$ below canopy. Using MEGAN (Model of Emissions of Gases and Aerosols from Nature), the emissions of isoprene and monoterpenes were estimated at 1.1 ton/year and 0.9 ton/year, respectively at Mt. Taehwa.