• 한국토양비료학회지
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• 제45권1호
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• pp.98-102
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• 2012

Organic farming has rapidly increased in Gangwon province, but there is a concern about nutrient accumulation and nutrient imbalance in the soil of organic farming. This study was conducted to investigate the impact of continuous application of organic amendments on growth and yield of red pepper and soil characteristics compared with chemical fertilizers application for four years. Treatments of organic amendments including oil cake, rice straw compost, amino acid compost, rice bran compost, and mushroom media (spent substrate) compost resulted in comparable growth and yield of pepper to chemical fertilizers. Organic amendments improved soil physical and chemical characteristics. Especially, rice bran compost and oil cake significantly increased soil organic matter compared with chemical fertilizer application and mushroom media compost and rice straw compost significantly improved soil aggregate stability. On the other hand, available phosphate level in the soil amended with rice bran compost or mushroom media compost was relatively high compared with the other treatments due to relatively high phosphate levels in the composts. It is not easy to adjust nutrient composition in the organic materials. Therefore, the results obtained from the study imply that nutrient imbalance needs to be carefully considered in organic farming without use of chemical fertilizers.

• 자원리싸이클링
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• 제28권3호
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• pp.15-20
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• 2019

폐수내 질소와 인을 이용한 struvite 회수는 수계 부영양화 방지 및 비료자원화에 효과적인 기술이나, 해결해야 할 이론 및 기술적 문제점이 있다. 본 연구에서는, 기존 문헌의 상세한 검토를 통하여, 이론적 측면에서 적절한 반응식 선정 및 이론적 고찰을 이용한 struvite 생성 반응예측 가능성을 논의하고, 기술적 측면에서는 struvite 생성의 대표적인 저해물질인 Ca의 배제를 통해 struvite 결정의 순도를 높일 수 있는 효과적인 방법을 소개하려 한다. 반응예측 측면에서는 중성~염기성 pH 영역에서 효과적인 struvite 반응식 및 반응계수를 이용, 정량적 모델을 구축할 수 있다. 이러한 모델은 실제 회분식 실험결과와 잘 일치하며 특히 이온들의 charge balance도 함께 고려하여 struvite 생성시 희석된 수용액에서 흔히 동반되는 pH 저하를 합리적으로 예측할 수 있다. 한편, Ca의 배제를 통한 struvite 순도 향상은 ${HPO_4}^{2-}-P$ 대비 고농도의 ${NH_4}^+-N$을 조성하여 해결할 수 있는데, 이는 고농도 암모늄 이온의 존재가 struvite 생성 관련 열역학적 구동력을 강화시켜 인산염이 Ca 대신 고농도 암모니아와 용이하게 반응하여 struvite 생성에 유리한 이온환경을 조성하기 때문이다. 즉 인산염이 $Ca^{2+}$과 빠르게 반응하여 이미 침전물이 형성하였을지라도, 고동도 암모늄으로 인한 열역학적 구동력으로 인산-칼슘 침전물이 재용해 되어 struvite를 생성시킬 수 있다.

• Journal of Nutrition and Health
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• 제37권2호
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• pp.100-107
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• 2004

This study was performed to evaluate the effect of dietary protein source and sulfur amino acid content on bone metabolism in ra. Thirty male rats (body weight 145$\pm$2g) were divided into three groups. The rats in the first group were fed on casein 20% diet as animal protein source and those in the second group were fed on soy 20% diet as plant protein source. Sulfur amino acid ratio of these group was 1.07:1. The rats in the third group were fed on soy 20% diet and the sulfur amino acid were supplemented with the amount contained as much in the soy 20% diet. All rats were fed on experimental diet and deionized water ad libitum for 9 weeks, The total body, spine, femur bone mineral density and bone mineral content were measured using Dual Energy X-ray Absorptiometry Calcium, phosphate, pyridinoline, creatinine in urine and calcium, phosphate, alkaline phosphatase, osteocalcin in serum were measured. During the experimental period, plant protein (soy protein) group had a lower urinary Ca excretion, urine pyridinoline ＆ crosslinks value and had a higher Ca efficiency in total bone and femur bone mineral density than animal protein (casein) group. There were no significant differences in serum calcium, phosphate, alkaline phosphatase and osteocalcin among the three groups of the rats. The findings from this study demonstrated that plant protein (soy protein) is beneficial of bone mineral density because it had a higher Ca efficiency in total bone and femur bone mineral density than animal protein (casein). However, the supplementation of sulfur amino acid on soy results were consistent with prior studies that dietary sulfur amino acid load had a negative effect on calcium balance. The rats fed sulfur amino acid supplementation diet increased urinary calcium excretion and decreased calcium efficiency for total and femur mineral density. Therefore, dietary protein source and sulfur amino acid content influence bone metabolism. (Korean J Nutrition 37(2): 100-107, 2004)

• 한국토양비료학회지
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• 제46권6호
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• pp.482-486
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• 2013

Assessment of nutrient balance in region unit is important to make a decision on nutrient management in agriculture. In this study, the nutrient demand in arable land and nutrient supply from livestock manure and chemical fertilizer were estimated from pig-concentrated areas. Three regions (H, I and J) were selected on the basis of pig numbers per unit area of arable land. In H and I regions, nitrogen amount from pig manure occupied about 50% of total livestock manure. Nutrient supply was three times higher compared to the nutrient demand in each of 3 regions. Soil available phosphate of higher pig-populated area in regional unit was higher than less populated livestock area. Therefore, livestock manure-derived regional management and monitoring of soil nutrient contents is necessary for the minimization and improvement of nutrient surplus.

• Asian-Australasian Journal of Animal Sciences
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• 제23권9호
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• pp.1127-1136
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• 2010

Yogurt gels are a type of soft solid, and these networks are relatively dynamic systems that are prone to structural rearrangements. The physical properties of yogurt gels can be qualitatively explained using a model for casein interactions that emphasizes a balance between attractive (e.g., hydrophobic attractions, casein cross-links contributed by calcium phosphate nanoclusters and covalent disulfide cross-links between caseins and denatured whey proteins) and repulsive (e.g., electrostatic or charge repulsions, mostly negative at the start of fermentation) forces. Various methods are discussed to investigate the physical and structural attributes of yogurts. Various processing variables are discussed which influence the textural properties of yogurts, such as total solids content, heat treatment, and incubation temperatures. A better understanding of factors contributing to the physical and structural attributes may allow manufacturers to improve the quality of yogurt.

• 한국토양비료학회지
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• 제36권5호
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• pp.344-355
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• 2003

우리나라는 농경지 단위면적 당 화학비료 시용량이 높은 국가로 분류되고 있다. 화학비료 시용량 저감을 위해 정부에서는 1990년 들어 다양한 정책적 지원을 지속해오고 있다. 본 연구에서는 1999년 전국의 시군을 대상으로 농가비료이용실태를 작물별, 농지이용유형별로 조사하여 1992년 농가비료이용실태와 비교하였다. 주요 작물에 대한 유기질비료의 평균 시용율은 최근 크게 감소하였으나, 시설재배지와 밭토양에서의 유기물 시용율은 1992년과 큰 변화가 없었다. 농가포장의 화학비료 시용율은 대부분의 곡류와 채소작물에서 다소 감소하는 경향을 보였다. 화학비료 중 질소질 비료 시용율 감소는 거의 없었으며, 인산과 칼리질 비료의 시용량 감소가 전체 화학비료 시용량에 감소에 영향을 주었다. 이러한 화학비료 시용량 감소에도 불구하고 대부분의 작물에 대한 비료사용량은 추천 시비량을 크게 초과하고 있었다. 양분 투입량과 회수량간 차이를 이용하여 계산된 양분수지를 계산한 결과, 질소의 과잉시용은 거의 감소되지 않고 있으나, 인산과 칼리의 시용량은 1992년에 비해 1999년 각각 21%와 13% 감소되었다. 결과적으로 정부와 관련기관의 적극적인 홍보에도 불구하고 1999년 현재까지 농가포장에서는 비료가 과잉시용되고 있었으며, 이를 개선하기 위해 토양검정치를 기준으로 산정한 추천시비량 수준으로 양분 시용량의 저감을 위한 효과적인 기술지원과 지도관리가 필요할 것으로 판단되었다.

• 한국동물학회지
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• 제28권4호
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• pp.257-278
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• 1985

Phenyalanine, tryptophan, tyrosine 과 같은 방향족 아미노산을 계배 초기에 투여하였을 때 somite 형성에 미치는 영향을 광학 및 전자현미경을 사용하여 형태적으로 추구한 결과 아미노산을 투여한 계배에서는 불완전한 체절 분절 현상이 일어나고 신경계에도 감쇠 영향을 미치며 somite의 발생이 불완전하고 그 크기도 다양하였다. 또한 체절 세포는 chromatin이 응축되고 미토콘드리아의 일부는 파괴되었고 핵이 변형된 경우도 있었다. 부란 24시간 후 아미노산을 투여하고 15일간 부란한 계배의 경우 단백질이나 핵산은 대조군에 비해 크게 저하되지는 않았으나 lactate dehydrogenase, succinate dehydrogenase, malate dehydrogenase 및 glucose 6-phosphate dehydrogenase와 같은 기초대사에 중요한 구실을 하는 효소활성은 크게 저하되었다. 이와 같은 실험결과로부터 초기계배에 아미노산을 투여하면 아마도 yolk granule의 분해가 지연되며 결과적으로 세포내의 아미노산 균형이 파괴되어 정상 대사가 이루어지지 못하여 비정상적인 체절형성의 현상이 나타나게 되는 것으로 생각된다.

• 한국가금학회지
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• 제28권1호
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• pp.1-6
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• 2001

Two experiments were carried out to evaluate the effects of adding phytase on nutrient availability and serum Ca and P level and to determine the effects of phytase on laying performance and egg quality in laying hens. In Exp. 1, twenty four laying hens(1.9kg average body weight and 78.4% egg production) were allotted to four treatments. Treatments included 1) corn-soybean meal based-control diet and 2), 3) and 4) control diet with phytase 200, 400 and 600 unit/kg, respectively. There were no significant effects of treatments on dry matter and nitrogen digestibility(P〉0.05). Ash, Ca and P digestibility in layer fed diet with phytase were greater than those in layer fed control diet(P〈0.05). Laying hens fed diets with phytase 200 and 400 unit retained more Ca than those fed other treatments (P〈0.05). No statistical difference was found for Ca exsretion(P〉0.05). P retention was greater for laying hens fed diet phytase 600 unit than other treaments(P〈0.05). P level in serum was higher for laying hens fed diets with phytase 400 and 600 unit than for laying hens fed other treatments. In Exp. 2, three hundred, IAS Brown layer, 40-week-old, divided into two treatment groups(control vs phytase supplementation without inorganic phosphate in the diets) with five replications per treatment and 30 layers per replication were fed the diets for 6 weeks. Egg production, egg weight and eggshell breaking strength and thickness were not different significantly(P〉0.05). In conclusion, phytase supplementation can be used to increase P utilization and retention in laying hens. Also, phytase supplementation was effective to spare inorganic phosphate in laying hen diets without any adverse effects on production performances.

• Asian-Australasian Journal of Animal Sciences
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• 제23권1호
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• pp.106-115
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• 2010

Phosphorylated dextran (P-Dex) is an acidic polysaccharide that functions as an immune adjuvant. P-Dex is known to regulate immune response by maintaining a balance between Th1 and Th2 cells in vitro, and thus may also be important in the control of allergic reactions. In the current study, we report the optimum conditions required for the efficient phosphorylation of dextran without toxicity. We found that when dextran was heated at 160${^{\circ}C}$ for 24 h in phosphate buffer (pH 5.0), the resulting P-Dex demonstrated the highest phosphorus content (6.8%). We also report that P-Dex enhances mitogenic activity in mouse splenocytes and induces expression of CD69 and CD86 on the surface of B cells and dendritic cells (DC) in vitro. Oral administration of P-Dex to ovalubmin (OVA)-immunized mice was found to reduce antigen-induced cell proliferation and suppress the expression of CD86 on Th2-inducing DC via exogenous OVA stimulation. P-Dex was also found to increase IL-10 expression in the splenocytes of treated mice. These findings suggest that oral administration of P-Dex increases immunological tolerance and improves the specificity of immunological response to specific antigens.

• Nutrition Research and Practice
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• 제3권3호
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• pp.200-207
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• 2009

This study examined the effects of com gluten (CG) and its hydrolysate consumptions on weight reduction in rats fed a high-fat diet. Eight-month-old male Sprague-Dawley rats (n=40) were fed a high-fat diet (40% calorie as fat) for 4 weeks. They were then randomly divided into four groups and fed the isocaloric diets with different protein sources for 8 weeks. The protein sources were casein (control group), intact CG (CG group), CG hydrolysate A (CGHA group, 30% of protein as peptides and 70% as free amino acids) and CG hydrolysate P (CGHP group, 93% of protein as peptides and 7% as free amino acids). Body weight gain, adipose tissue weights, nitrogen balance, absorptions of energy, protein and fat, lipid profiles in plasma, liver and feces and hepatic activities of camitine palmitoyl transferase (CPT), fatty acid synthase (FAS), malic enzyme (ME) and glucose-6-phosphate dehydrogenase (G6PDH) were assessed. The CGHA diet had the highest amount of BCAAs, especially leucine, and most of them existed as free amino acid forms. The CGHA group showed significant weight reduction and negative nitrogen balance. Protein absorption and apparent protein digestibility in the CGHA group were significantly lower than those in other groups. Adipose tissue weights were the lowest in the CGHA group. Activity of CPT tended to be higher in the CGHA group than in other groups and those of FAS, ME and G6PDH were significantly lower in the CGHA group than in other groups. In conclusion, the CGHA diet which had relatively high amounts of free amino acids and BCAAs, especially leucine, had a weight reduction effect by lowering adipose tissue weight and the activities of FAS, ME and G6PDH in experimental animals, but it seemed to be a negative result induced by lowering protein absorption, increasing urinary nitrogen excretion and protein catabolism.