• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.169-176
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• 2012

Among the major nutrients, phosphorus is by far the least mobile and available to plants in most soil conditions. A large portion of soluble inorganic phosphate applied to soil in the form of phosphate fertilizers is immobilized rapidly and becomes unavailable to plants. To improve the plant growth and yield and to minimize P loss from soils, the ability of a few soil microorganisms converting insoluble forms into soluble forms for phosphorus is an important trait in several plant growth-promoting microorganisms belonging to the genera Bacillus and Pseudomonas and the fungi belonging to the genera Penicillium and Aspergillus in managing soil phosphorus. The principal mechanism of solubilization of mineral phosphate by phosphate solubilizing bacteria (PSB) is the release of low molecular weight organic acids such as formic, acetic, propionic, lactic, glycolic, fumaric, and succinic acids and acidic phosphatases like phytase synthesized by soil microorganisms in soil. Hydroxyl and carboxyl groups from the organic acids can chelate the cations bound to phosphate, thereby converting it into soluble forms.

• Korean Journal of Agricultural Science
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• v.48 no.3
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• pp.447-454
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• 2021

This study was conducted to evaluate the effects of different copper sources (inorganic and organic) on the growth performance, fecal copper excretion, intestinal morphology, and health in growing pigs. A total of 40 growing pigs (30.22 ± 1.92 kg) were randomly assigned to 5 dietary treatments: a basal control diet (CON), 4 experimental diets supplemented with either copper sulfate (CuSO₄), Cu-glycine complex (CuGly), Cu-amino acid complex (CuAA), or Cu-hydroxy-4-methylthio butanoate chelate complex (CuHMB) at 100 ppm, respectively. At the end of the study (28 days), fecal and blood samples were collected, and the pigs were slaughtered to determine the intestinal morphology. During the 28 days of the experimental period, pigs fed the inorganic and organic copper showed a higher average daily gain (p < 0.01) and gain feed ratio (p < 0.01). There were no differences in mineral concentrations of the serum; however, the copper concentration of the feces was lower (p < 0.01) in the CuAA and CuHMB groups. The intestinal morphology and blood profiles did not significantly differ between the groups. In conclusion, the organic copper sources (CuAA and CuHMB) can be used as a growth promoter to replace the CuSO₄ without any negative effects on health in growing pigs and to reduce fecal copper excretion.

• Journal of Animal Science and Technology
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• v.63 no.6
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• pp.1386-1396
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• 2021

Copper is an essential mineral for pigs, thus it is used as a feed additive in the forms of copper sulfate. Therefore, this study aimed at characterizing the fecal microbiota shifts in pigs as fed by different forms of copper supplementation. 40 growing pigs aged 73 ± 1 days with an average weight of 30.22 ± 1.92kg were randomly divided into 5 groups. The control group (CON) fed with basal diet, while treatment groups were fed a basal diet supplemented with 100 ppm/kg of copper sulfate (CuSO₄), Cu-glycine complex (CuGly), Cu-amino acid complex (CuAA), and Cu-hydroxy(4methylthio)butanoate chelate complex (CuHMB) for 28 days of trial, respectively. The data presented the comparison between inorganic and organic copper supplementation through gut microbiota in growing pigs. Alpha and Beta diversity anaylsis resulted in copper supplementation did shifted gut microbioal community structure. At the phylum level, Firmicutes and Bacteroidetes were the most abundant phyla at all times regardless of treatment. At the genus level, the relative abundances of Prevotella, Lactobacillus, Megasphaera, and SMB53 of the CuGly and CuHMB groups were significantly higher than those of copper sulfate and basal diet groups. Overall, this study may provide the potential role of organic copper replacing inorganic copper, resulting in increased beneficial bacteria in the pig gut.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1035-1041
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• 2011

Salinity of soil under the plastic film houses in Korea is known as a significant factor to lower the crop production and to hamper the sustainable agricultural land management. In this study we propose a field monitoring technique to examine the methods applied to minimize the adverse effect of salts in soil based on the relationship between soil electrical characteristics and soil properties. Field experiments for 4 different treatments (water only, fertilizer only, DTPA only, and DTPA and fertilizer together) were conducted on soils at the plastic film house built for cultivating a cucumber plant located at Chunan-si, Chungchungnam-do in Korea. The electrical resistivity was measured by both a dipole-dipole and wenner multi-electrodes array method. After the electrical resistivity measurement we also measured the soil water content, temperature, and electrical conductivity on surface soil. The resulted image of the interpreted resistivity by the inversion technique presented a unique spatial distribution depending on the treatment, implying the effect of the different chemical components. It was also highly suspected that resistivity response changed with the nutrients level, suggesting that our proposed technique could be the effective tool for the monitoring soil water as well as nutrient during the cropping period. Especially, subsoils under DTPA treatment at 40 to 60 cm depth typically presented lower soil water accumulation comparing to subsoils under non-DTPA treatment. It is considered that DTPA resulted in increase of a root water uptake. However, our demonstrated results were mainly based on qualitative comparison. Further experiments need to be conducted to monitor temporal changes of electrical resistivity using time lapse analysis, providing that a plant root activity difference based on changes of soil water and nutrients level in time.

• Korean Journal of Poultry Science
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• v.27 no.2
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• pp.115-132
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• 2000

Eggshell strength and eggshell pigmentation are described in this paper since these are needed for quality egg production. A strong eggshell is determined by the components of the shell (cuticle, true shell and membranes) as well as the proper function of the gastrointestinal tract, the shell gland, the Kidneys and the endocrine system. When the puller reaches sexual maturity, the medullary bone must be ready for the laying hen at the peak egg shell formation. The amount of calcium in the layer diet, sources of calcium feed, the ratio of calcium and phosphorus in the layer diet, adequate levels of vitamin D and the dietary mineral (electrolyte) balance in the body fluid are important factors along with the levels of other nutrients. Biological, environmental and managerial factors such as the age of laying flock, temperature and humidity of the hen house, bird strain, disease, egg collection through transportation and others and influence the shell breakage at various stages of movement of the eggs from the producer to the consumer. The pigments present in eggshells are protoporphyrin-Ⅸ, biliverdin-Ⅸ and its zinc chelate and occasional traces of coproporphyrin-Ⅲ. However, there are several causes of changes in eggshell pigmentation such as the age of hen, disease, drugs and surface defects due to abnormal post-cuticular deposits.