• 한국식품위생안전성학회지
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• 제8권4호
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• pp.215-223
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• 1993

클로람페니콜은 광벙위 항생물질로서 수의축산분야에서 널리 사용되어 왔으나 이 제제의 잠재적인 독성과 축산식풍 중 잔류성 때문에 세계 각국에서는 식용동물에서의 사용을 금지하고 있다. 따라서 이 시험에서는 미생물학척 방법에 의한 우유 및 식육 중 미량의 잔류클로람페니콜을 측정할 수 있는 방법을 확립하고자 M. luteus ATCC 9341을 시험용 균주로 설정하여 다음과 같은 결과를 얻었다. 1. 검출감도를 향상시키고자 시험명판용 Mueller-Hinton 배지의 배지량을 최소화하고 ethylacetate로 추출 농축하여 ml당 0.15/lg의 옥시테트라사이클린을 첨가한 회석용 인산염 완충액 (pH 6.0) 으로 잔류물을 용해하여 사용하였을 때 가기장 좋은 검출강도를 나타내였다. 2. 시료별 최저검출농도는 원유가 0.025 ppm이었으며, 식육은 0.05 ppm까지 검출할 수 있었다. 3. 시료별 평균 회수율은 원유가 68.5%이었으며, 쇠고기, 돼지고기 및 닭고기는 각각 65.1%. 63.8% 및 59.4%이었다. 이들 시료의 회수율에 대한 변이계수 (CV)는 1.8~15.1%이었다.

• Genomics & Informatics
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• 제13권4호
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• pp.146-151
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• 2015

Previous studies in Holstein have shown 35% to 51.8% heritability in milk production traits, such as milk yield, fat, and protein, using pedigree data. Other studies in complex human traits could be captured by common single-nucleotide polymorphisms (SNPs), and their genetic variations, attributed to chromosomes, are in proportion to their length. Using genome-wide estimation and partitioning approaches, we analyzed three quantitative Holstein traits relevant to milk production in Korean Holstein data harvested from 462 individuals genotyped for 54,609 SNPs. For all three traits (milk yield, fat, and protein), we estimated a nominally significant (p = 0.1) proportion of variance explained by all SNPs on the Illumina BovineSNP50 Beadchip ($h^2_G$). These common SNPs explained approximately most of the narrow-sense heritability. Longer genomic regions tended to provide more phenotypic variation information, with a correlation of 0.46~0.53 between the estimate of variance explained by individual chromosomes and their physical length. These results suggested that polygenicity was ubiquitous for Holstein milk production traits. These results will expand our knowledge on recent animal breeding, such as genomic selection in Holstein.

• 대한수의학회지
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• 제26권2호
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• pp.237-243
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• 1986

This paper deals with the incidence of bovine mastitis for 743 quarters and distribution of Staphylococci for the quarter and 70 bulk milk samples in the northern area of Gyeongbuk during the period from January to December 1984. Isolated Staphylococci were examined for species, subgroups, antibiotic resistance and penicillinase production. The results obtained were summarized as follows : A total of 25(73.5%) of 34 herds, 102(54.3%) of 188 cows and 208(30.3%) of 743 quarters were found to be infected with subclinical mastitis. A total of 83(83.1%) of 102 cows, 94(45.2%) of 208 mastitic quarters and 55(78.6%) of 70 bulk milk samples were isolated Staphylococci. Three hundred and eighteen strains of Staphylococci were classified into 11 species. Of these speoies, S. aureus from mastitis and S. sciuri from bulk milk were found most frequently, followed by S. epidermidis, S. simulans, S. cohnii, S. haemolyticus, S. xylosus, S. hyicus subsp. chromogenes, S. saprophyticus, S. warneri, S hyicus subsp. hyicus. Subgroups of catalase-positive and negative cocci were belonged most frequently to subgroup I, and subgroups III and III b, respectively. The method of Pelzer of al(97.8%) was more classified than that of Baird-Parker (68.5%). One hundred and sixty one strains(50.6%) of 318 Staphylococci isolates were resistance to one or more antibiotics such as ampicillin, chloramphenicol, gentamicin, kanamycin, streptomycin, and tetracycline. Isolates from subclinical mastitis were more resistant to antibiotics than its from bulk milk. Of the 318 Staphylococci Isolates, 128(40.3%) gave positive reaction for the penicillinase test, all of ampicillin resistance strains produced this emzyme.

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
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• pp.85-85
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• 2003

Human lactoferrin (hLF) is an 80 kDa iron-binding glycoprotein that is expressed in high concentration in milk and in lesser amount in the secondary or specific granules of neutrophils and in plasma, LF is classically considered to be related to the binding, transport, and storage of iron. The transgenic mice carrying the human hLF gene in conjunction with the bovine $\beta$-casein promoter produced the human hLF in their milk during lactation. To screen transgenic mice, PCR was carried out using chromosomal DNA extracted from tail or toe tissues. In this study, stability of germ line transmission and expression of hLF were monitored up to generation Fl7 of a transgenic line. When female mouse of generation F9 was crossbred with normal male, generation F9 to Fl7 mice showed similar transmission rates ($66.0 \pm 12.57%, 42.0 \pm 14.98%, 72.2 \pm 25.45%, 50.0 \pm 16.70%, 65.7 \pm 6.45%, 48.6 \pm 14.65%, 54 1 \pm 18 11%, 57.8 \pm 16.16% and 48.6 \pm 20.66$, respectively), implying that the hLF gene can be transmitted stably up to long term generation in the transgenic mice For ELISA analysis, hLF expression levels were determined with an hLF ELISA kit in accordance with the supplier's protocol. Expression levels of human hLF from milk of generation F9 to Fl3 mice were $ 3.2 \pm 0.69 mg/ml, 3.1 \pm 0.81 mg/ml, 4.6 \pm 1.38 mg/ml, 3.1 \pm 0.42 mg/ml, and 4.5 \pm 1,48 mg/ml$, respectively. These expression levels were lower than that of founder (6.6 mg/$m\ell$) mouse. We concluded that transgenic mice faithfully passed the transgene on their progeny and successively secreted target proteins into their milk through several generations.

• 대한수의학회지
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• 제29권3호
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• pp.393-405
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• 1989

This study was carried out to treatment test for bovine mastitis by the determination of adenosine triphosphate (ATP) based on firefly bioluminescence. The results obtained are followed; 1. In the susceptibility test, cephalothin which looks the most effective were sensitive to Staphylococcus sp. (72.3%), Micrococcus sp. (84.2%), Streptococcus sp. (72.7%) and Gram positive bacilli (72.7%), Gram negative bacilli were sensitive to gentamicin (92.3%) and Yeast-like-fungi was the most sensitive to clotrimazole, and nystatin in order. 2. When the number of bacteria, such as Staphylococcus aureus, Candida tropicalis isolated from the mastitis milk were counted by conventional agar plating technique, and compared with the concentration of bacterial ATP, it gave a good linear relationship. The content of ATP per Staphylococcus aureus, cell was 3.1fM and Candida tropicalis showed the high level of A TP (90fM). 3. The ATP assay was applied to the determination of minimal inhibitory concentration (MIC) of various antibiotics. When Staphylococcus aureus was incubated in the presence of different concentration of tetracycline, erythromycin, kanamycin and streptomycin sulfate and the growth was monitored by the conventional agar plating technique and ATP assay, both methods shown the same results that they were 1mcg/ml, 2mcg/ml, 6.25mcg/ml and 8mcg/ml, respectively. 4. For the determination of susceptibility of sensitive and resistant Staphylococcus au reus isolated for the milk with mastitis to tetracycline, erythromycin kanamycin and streptomycin sulfate, the minimum time required for the test was determined by the assay of ATP every 30 minutes during incubation of 3 hours at $37^{\circ}C$. ATP concentration time curve calculated on both resistant and sensitive strains incubated 3 hours as the optimum time for the determination of susceptibilities of various antibiotics exemed. The ATP concentration of each test broth (antibiotic containing), expressed as a percentage of its own control brith (antibioticfree) indicated values of 30% to be indicative of each antibiotic sensitivity. Single time point ATP assay carried out on the various sensitive and resistant of Staphylococcus aureus to antibiotics examined after 3 hours at $37^{\circ}C$ correlated exactly with disc diffusion and MIC. 5. In the cure of intramammary treatment of bovine mastitis in lactating quarters, the cure rate of Staphylococcal mastitis showed to cephalexin (80%), cloxacillin and gentamicin (70%), ampicillin and oxytetracycline (60%), and Streptococcal mastitis showed to cephalexin (85%), penicillin (80%), cloxacillin and oxytetracycline (75%), and ampicillin (70%), but intramammary antimycotic drug (clotrimazol) were only a little effect about fungal mastitis.

• 한국식품위생안전성학회지
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• 제39권3호
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• pp.181-190
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• 2024

소 유방염 관련 대장균(BMEC)은 생산되는 우유의 양과 품질을 변화시키고 도태율을 높임으로써 전 세계 낙농 산업에 심각한 재정적 손실을 초래할 수 있는 주요 원인 물질로 간주된다. 연구자, 수의사, 농부가 가장 효과적인 치료법과 진단 기술을 이해하고 결정하는 것은 젖소 유방염을 극복하는데 중요하다. 특히 무증상 혹은 준임상형 유방염의 경우, 소는 뚜렷한 증상을 보이지 않고, 장기간에 걸쳐 겉보기에 정상적인 우유를 계속 분비하여 원인 병원체인 대장균이 무리 내에서 감염을 퍼뜨릴 수 있다. 유방염 예방을 위해서는, 병원균의 유방 내 침입, 감염 확립, 유방의 염증의 3단계 병인 과정에 대한 이해가 필수적이다. 지금까지 대장균 유방염의 임상적 중증도에 기여하는 독성 인자와 병원성 사이에 명확한 상관관계가 발견되지 않았다. 다제내성 대장균과 새로운 내성 기전의 진화는 유방염 치료에 항생제를 광범위하게 사용하고 있기 때문에 문제시 되고 있는 실정이다. 따라서 BMEC 치료의 효능을 향상시키기 위해서는 대체제 발굴이 중요하다. 지난 30년 동안 소 유방염의 역학 조사를 위해 다양한 유전자형 분석 기술이 사용되었다. 이러한 연구는 BMEC 계통 간의 진화 관련성 뿐 아니라 기원, 전염 경로, 개체군 구조에 대한 이해를 크게 향상시켰다. 따라서 본 리뷰에서는 BMEC의 전반적 개요를 제공하여 병인, 유전적 관계, 발병 기전, 관리 및 질병 통제를 위한 새로운 치료 옵션에 대한 통찰력을 제공하고자 한다.

• Journal of Dairy Science and Biotechnology
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• 제26권1호
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• pp.1-4
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• 2008

본 연구는 숙면 유도 호르몬으로 알려진 멜라토닌의 원유 및 유제품 내 함량을 방사면역측정법으로 분석하였으며, 그 결과는 다음과 같다. 1. 착유 시간에 따른 멜라토닌 함량은 새벽 4시에 착유한 원유 샘플의 멜라토닌 함량이 평균 $6.90{\pm}3.55pg/mL$로 나타났으며, 저녁 7시 및 낮 12시 착유 원유 샘플은 각각 $2.01{\pm}1.47pg/mL$와 $0.16{\pm}0.04pg/mL$로 나타나 새벽 착유 원유 내 멜라토닌 함량이 유의적으로 높은 결과를 나타내었으며, 이는 로봇 착유기를 사용하는 농가에서도 심야 및 새벽 착유 원유에서 멜라토닌 함량이 가장 높게 나타나 2개 목장 모두 비슷한 결과를 나타내었다. 2. 일반 우유 제품과 나이트 밀크 제품 간 멜라토닌 함량비교 시, 나이트 밀크의 멜라토닌 함량이 약 5배 정도 높은 결과를 보였다. 3. 일반 우유를 대상으로 원유, 균질 및 살균 등의 공정이 멜라토닌 함량에 영향을 미치지 않는 것으로 나타났으나, 그 수준은 매우 낮은 농도로 존재하였다.

• 한국가정과교육학회지
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• 제12권2호
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• pp.47-64
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• 2000

The purpose of this study was to search the calcium and iron rich foods in Korean people. The food sources presented in the current home economics textbooks of middle and high school were investigated. And 40 kinds of calcium and iron rich foods were selected by the quantity in 100g edible portion. one serving size and according to 1997 food supply data. Also 3 major food groups of calcium and iron supply in Korean were identified, and 10 rich foods for each food groups were selected. The results were summarized as follows. 1. The food sources of calcium 1) The food sources of calcium presented in the home economics textbooks of middle and high school are milk and dairy products. small fishes such as anchovy icefish and dried strip and green vegetables etc. 2) The calcium rich foods by 100g edible portion were in order of skim milk powder river snail sesame sea mustard. whole milk powder. snapping turtle loach sea tangle(dried) opossum shrimp and sea lettuce(dried). And the calcium rich foods by the calcium content in one serving were in order of river snail snapping turtle opossum shrimp loach spiny lobster skate skim milk powder small alaska pollack freshwater crab condensed milk whole milk powder skate ray and milk. 3) The 3 major calcium supply food groups in Korean were vegetables fish and shellfishes and milk and dairy products. 4) The calcium supply foods according to the quantity of food supply in 1997 was in order of sea mustard, milk anchovy chinese cabbage soybean skin milk powder laver shrimp welsh onion and maize. The vegetables were the important sources of calcium in Korean. 2. The food sources of iron 1) The food sources of iron which are commonly presented in the textbooks of middle and high school were meat liver egg(egg yolk) and green vegetables etc 2) The iron rich foods on the basis of the iron content in 100g edible portion were in order of surf clam marsh clam laver(dried)( sea lettuce(dried), crayfish pelilla seed little neck clam orient hard clam, venus clam, and freshwater carab. And the iron rich foods by the iron content in one serving were in order of surf clam marsh clam crayfish little neck clam orient hard clam freshwater crab venus clam hen cockle green confertii(fresh) pen shell and spiny lobster. 3) The 3 major iron supply food groups in Korean were cereals an cereal products fishes and shellfishes and vegetables. 4) The iron supply food according to the quantity of food supply in 1997 was in order of soybean sea mustard maize rice meat edible viscera laver wheat flour, pook, red pepper, egg and bovine meat.

• 한국식품위생안전성학회지
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• 제27권1호
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• pp.63-67
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• 2012

동물성 식품 유래 장구균의 항생제 내성은 내성균주 또는 내성 유전자가 먹이사슬을 통해 인체로 전달될 수 있다는 가능성 때문에 공중보건학적으로 중요하게 대두되고 있다. 본 연구는 원유 시료에서 분리된 장구균의 tetracycline에 대한 내성을 표현형 및 유전형 수준에서 분석하였다. 원유 시료에서 총 245주의 장구균을 분리하였으며 그 중 $E.$ $faecalis$ 가 199주로 전체의 81.2%를 차지 하였으며 그 외에 $E.$ $faecium$ 이 25주(10.2%), $E.$ $avium$ 이 7주(2.9%), $E.$ $durans$ 이 6주(2.5%), $E.$ $gallinarum$ 이 4주(1.6%), $E.$ $raffinosus$ 이 4주(1.6%)의 비율로 분리되었다. 분리 균주중 76.3%에 해당하는 187주가 tetracycline에 내성을 나타내었으며 내성균주의 83.4%에 해당하는 156주가 $tet$(M)을 26.7%에 해당하는 50주가 $tet$(S)를 16.1%에 해당하는 30주가 $tet$(L)을 3.2%에 해당하는 6주가 $tet$(M) + $tet$(L) + $tet$(S)의 3개의 유전자를 동시에 소유하고 있는 것으로 분석되었다.

• Journal of Animal Science and Technology
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• 제63권5호
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• pp.1126-1141
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• 2021

Recent evidence has shown that methionine (Met) supplementation can improve milk protein synthesis under hyperthermia (which reduces milk production). To explore the mechanism by which milk protein synthesis is affected by Met supplementation under hyperthermia, mammary alveolar (MAC-T) cells were incubated at a hyperthermic temperature of 42℃ for 6 h in media with different concentrations of Met. While the control group (CON) contained a normal amino acid concentration profile (60 ㎍/mL of Met), the three treatment groups were supplemented with Met at concentrations of 10 ㎍/mL (MET70, 70 ㎍/mL of Met), 20 ㎍/mL (MET80, 80 ㎍/mL of Met), and 30 ㎍/mL (MET90,90 ㎍/mL of Met). Our results show that additional Met supplementation increases the mRNA and protein levels of BCL2 (B-cell lymphoma-2, an anti-apoptosis agent), and decreases the mRNA and protein levels of BAX (Bcl-2-associated X protein, a pro-apoptosis agent), especially at an additional supplementary concentration of 20 ㎍/mL (group Met80). Supplementation with higher concentrations of Met decreased the mRNA levels of Caspase-3 and Caspase-9, and increased protein levels of heat shock protein (HSP70). The total protein levels of the mechanistic target of rapamycin (mTOR) and the mTOR signalling pathway-related proteins, AKT, ribosomal protein S6 kinase B1 (RPS6KB1), and ribosomal protein S6 (RPS6), increased with increasing Met supplementation, and peaked at 80 ㎍/mL Met (group Met80). In addition, we also found that additional Met supplementation upregulated the gene expression of αS1-casein (CSN1S1), β-casein (CSN2), and the amino acid transporter genes SLC38A2, SLC38A3 which are known to be mTOR targets. Additional Met supplementation, however, had no effect on the gene expression of κ-casein (CSN3) and solute carrier family 34 member 2 (SLC34A2). Our results suggest that additional Met supplementation with 20 ㎍/mL may promote the synthesis of milk proteins in bovine mammary epithelial cells under hyperthermia by inhibiting apoptosis, activating the AKT-mTOR-RPS6KB1 signalling pathway, and regulating the entry of amino acids into these cells.