• 한국축산식품학회지
• /
• 제30권3호
• /
• pp.443-448
• /
• 2010

유제품, 김치 및 신생아 분변 등에서 유산균을 분리하여 우유 casein을 분해시켜 배양상등액에 존재하는 serine의 함량을 측정함으로써 간접적으로 CPP 생산을 평가하였다. CPP 생산 능력은 OPA방법으로 측정했을 때 E. faecalis A-2 균주가 1.244 mg/mL로 가장 많은 peptide를 생산 하였다. 본 실험에 사용된 유산균의 경우, 세포내 효소와 세포외 효소로 각각 나누어 proteolytic 활성을 평가한 결과 세포내 효소에 의한 proteolytic 활성은 E. faecalis A-6 균주가 가장 높은 것으로 나타났으며, 세포외 효소에 의한 proteolytic 활성은 L. plantarum A-14 균주에서 가장 높게 나타났다. 가용성 칼슘함량은 Leuconostoc mesenteroides A-1(11 mg/dL), E. durans A-16(10.481 mg/dL), 그리고 L. planatarum A-3(10.356 mg/dL) 균주의 경우에는 대조구보다 높은 유리 칼슘함량을 나타내었다. 따라서 이러한 유산균을 이용한다면 소장 내에서 칼슘 흡수를 극대화시킬수 있는 장점이 있어 이들 유산균을 이용한 고칼슘 제품 개발이 가능할 것이다.

• 농업과학연구
• /
• 제36권2호
• /
• pp.167-177
• /
• 2009

본 연구는 한국형 Holstein종 젖소집단의 DGAT1 유전자의 특성을 구명하고, DGAT1의 유전적 다형과 산유형질인 유량 및 유지량 간의 연관성을 구명하여 젖소집단의 유전적 개량을 위한 분자유전학적 접목을 위하여 실험을 실시하였다. Holstein종의 genomic DNA로부터 PCR기법을 이용하여 DGAT1 유전자좌를 specific primers로 증폭한 후, 1.5% agarose gel에 전기영동한 결과 411 bp의 단편이 양호하게 증폭되었음을 확인하였다. DGAT1 유전자의 염기서열을 분석한 결과 DGAT1 Q 대립유전자의 216-218 bp의 염기서열이 AUG(lysine, K)였으나, 동위치의 대립유전자 q의 염기서열은 GCG(alanine, A)로 치환되어 있음을 확인할 수 있었다. 한편 한국 Holstein종과 NCBI에서 보고된 bovine DGAT1 유전자 단편의 염기서열간에는 100% 상동성을 보였다. 한국 Holstein종 유우집단의 DGAT1 유전자형의 분포는 DGAT1 QQ, Qq 및 qq 유전자 분포가 각각 16.43, 36.43 및 47.14%로 qq 유전자형빈도가 다른 유전자형에 비하여 높았으며, 유전자빈도는 DGAT1 Q 및 q 빈도가 각각 0.35 및 0.65로 q의 빈도가 높았다. DGAT1 유전자형과 산유량인 유량 및 유지량간의 연관성에 있어서는 DGAT1 유전자형이 유량 및 유지량에서 유의적인 차이 (P<0.05)를 보였으며, DGAT1 Qq 유전자형이 QQ 및 qq 유전자형에 비하여 유량과 유지량에서 유의적인 차이(P<0.05)로 높은 수치를 나타냈다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제33권1호
• /
• pp.111-119
• /
• 2020

Objective: This study was conducted to examine the effects of a mixture of pinecone oil, garlic, and brown seaweed extracts (PGBE) on milk production traits as well as physiological and ethological parameters in Holstein cows during the summer season (24 May to 03 July 2015, Korea). Methods: Among the extract combinations tested, we found that the level of 2,2'-azino-bis (3-ethylberzothiazoline-6-sulphonic acid) cation radical scavenging activity of the 0.16% PBGE complex at ratio of 1:1:1 (vol/vol) was comparable to that of the control (ascorbic acid; 1 mg/mL). Additionally, the PBGE complex reduced lipopolysaccharide-induced COX-2 expression in bovine mammary epithelial cells. Based on these findings, 40 lactating Holstein cows were used to measure the effects of PBGE complex at ratio of 1:1:1 (vol/vol) on milk production, immune response, metabolites, and behavior patterns by dividing the cows into two groups fed diets containing PGBE complex (n = 20; 0.016%/kg feed dry matter basis) or not containing PGBE complex (control, n = 20) for 40 d. Results: Results showed that PGBE complex did not influence milk composition, eating and ear surface temperature patterns, immune response, or metabolic parameters but promoted average milk yield throughout the experimental period. Additionally, a tendency of higher total antioxidant capacity and glutathione in the PGBE group was observed compared to the those in the control. When the temperature-humidity index (THI) exceeded 72 (average THI = 73.8), PGBE complex-fed cows experiencing heat stress showed increased milk yield and a tendency of increased rumination compared to the control. Conclusion: We suggest that incorporation of a combined mixture of 0.016% PGBE (1:1:1 ratio, vol/vol) to diet has the potential to improve milk yield and health status of cows under mild to moderate heat stress, denoting that it might be useful as an alternative anti-stressor in the diet of dairy cows under hot conditions.

• 한국식품과학회지
• /
• 제28권6호
• /
• pp.1184-1187
• /
• 1996

우유 중에 존재할 수 있는 발암성 진균독소의 하나인 $aflatoxin{\;}M_1{\;}(AFM_1)$을 신속, 간편하게 분석할 수 있는 효소면역측정법(ELISA)을 개발하고자 하였다. 소혈청알부민에 공유결합한 $AFM_1\;(AFM_1-BSA)$을 토끼에 면역하여 항체를 생산하고 정제하였다. 이 항체의 유사독소와의 교차반응율은 29.9%이하의 비교적 낮은 교차율을 나타냈다. $AFM_1$의 검출을 위하여 확립한 직접경합ELISA (cdELISA)로 우유에 인위적으로 오염시킨 $AFM_1$을 정제과정없이 ELISA로 분석하는 경우, 우유를 PBS로 40%되게(2:3) 희석하였을 때 양호한 회수율을 보였다. 이 조건하에서 행한 ELISA의 $AFM_1$분석 회수율은 0.3-3.0 ng/ml의 오염농도 범위에서 농도별 회수율로 평균 113%, 그 분산은 8.2%였다. 본 연구에서 개발한 ELISA system은 우유 중의 0.5 ppb이상의 $AFM_1$을 정제과정없이 손쉽게 분석하는데 유용할 것으로 판단된다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제21권5호
• /
• pp.617-623
• /
• 2008

A fine-mapping method exploiting linkage disequilibrium was used to detect quantitative trait loci (QTL) on the X chromosome affecting milk production, body conformation and productivity traits. The pedigree comprised 22 paternal half-sib families of Black-and-White Holstein bulls in the Netherlands in a grand-daughter design for a total of 955 sons. Twenty-five microsatellite markers were genotyped to construct a linkage map on the chromosome X spanning 170 Haldane cM with an average inter-marker distance of 7.1 cM. A covariance matrix including elements about identical-by-descent probabilities between haplotypes regarding QTL allele effects was incorporated into the animal model, and a restricted maximum-likelihood method was applied for the presence of QTL using the LDVCM program. Significance thresholds were obtained by permuting haplotypes to phenotypes and by using a false discovery rate procedure. Seven QTL responsible for conformation types (teat length, rump width, rear leg set, angularity and fore udder attachment), behavior (temperament) and a mixture of production and health (durable prestation) were detected at the suggestive level. Some QTL affecting teat length, rump width, durable prestation and rear leg set had small numbers of haplotype clusters, which may indicate good classification of alleles for causal genes or markers that are tightly associated with the causal mutation. However, higher maker density is required to better refine the QTL position and to better characterize functionally distinct haplotypes which will provide information to find causal genes for the traits.

• 한국축산식품학회지
• /
• 제36권4호
• /
• pp.487-493
• /
• 2016

The antimicrobial activity of bovine lactoferrin hydrolysates (bLFH) was measured against Pseudomonas strains (P. syringae and P. fluorescens) in vitro. To compare susceptibility to bLFH, minimal inhibitory concentration (MIC) values were determined using chemiluminescence assays and paper disc plate assays. Antimicrobial effect against P. fluorescens was not observed by either assay, suggesting that bLFH did not exhibit antimicrobial activity against P. fluorescens. However, a significant inhibition of P. syringae growth was observed in the presence of bLFH. The addition of bLFH in liquid or solid medium inhibited growth of P. syringae in a dose-dependent manner. Furthermore, a bLFH peptide with antimicrobial activity toward P. syringae was isolated and identified. The N-terminal amino acid sequences of thus obtained antimicrobial bLFH peptides were analyzed by a protein sequencer and were found to be Leu-Arg-Ile-Pro-Ser-Lys-Val-Asp-Ser-Ala and Phe-Lys-Cys-Arg-Arg-Trp-Gln-Trp-Arg-Met. The latter peptide sequence is known to be characteristic of lactoferricin. Therefore, in the present study, we identified a new antimicrobial peptide against P. syringae, present within the N-terminus and possessing the amino acid sequence of Leu-Arg-Ile-Pro-Ser-Lys-Val-Asp-Ser-Ala.

• 대한수의학회지
• /
• 제14권1호
• /
• pp.91-97
• /
• 1974

A total of 820 dairy cattle were examined formastitis by California mastitis test method and 181 dairy cattle were examined bacteriologically according to the method of Connecticut mastitis control program. The results obtained were as followings: 1. Milk samples from 1.231(38.1%) of 3,225 quarters and 568(69.3%) of 820 dairy cattle were positive for mastitis by California mastitis test method. 2. Among 181 cattle examined bacteriologically by the method of Connecticut mastitis control program 159(22.9%) quarters of 102(56.4%) cattle were infected. Clinical mastitis was found in 5 cattle. 3. Important causative organisms were found to de Staphylococcus aureus(44.8%), Streptococcus agalactiae(21.5%), and non-str, agalactiae Streptococcus(26.4%). Corynebacterium ssp., Pseudomonas spp., Coliforms and Yeasts were also occasionally found to be causative organisms. 4. Strains of Staphylococcus aureus isolated from bovine udders were tested for sensitivity to antibiotics. The rates of resistant strain were 13.7%, 11.8%, 8.8%, 5.9%, 100%, 4.9% and 4.9% for penicillin G, streptomycin, terramycin, erythromycin, chloramphenicol, ampicillin and kanamycin, respectively.

• Journal of Microbiology and Biotechnology
• /
• 제20권10호
• /
• pp.1446-1449
• /
• 2010

A total of 1,444 coagulase-negative staphylococci (CNS) isolates from bovine mastitic milk samples collected during 2003-2008 in Korea were identified to the species level. Of 14 species identified, S. simulans, S. haemolyticus, and S. sciuri accounted for over 60% of the isolates. All the CNS isolates were tested for susceptibility to eight antimicrobials commonly used in dairy cattle. With a few exceptions, similar resistance patterns were observed among the CNS species: penicillin and ampicillin showed the lowest activity, whereas amikacin, cephalothin, and gentamicin were highly effective. About 39% (557/1,444) of the CNS isolates were pan-susceptible, whereas 12% (175/1,444) showed resistance to four or more antimicrobials tested.

• Journal of Microbiology and Biotechnology
• /
• 제28권8호
• /
• pp.1299-1309
• /
• 2018

We previously reported on lactophoricin (LPcin), a cationic ${\alpha}-helical$ antimicrobial peptide derived from bovine milk, which has antimicrobial effects on Candida albicans as well as Gram-positive and Gram-negative bacteria. In this study, we designed the LPcin-YK3 peptide, a shorter analog of LPcin, and investigated its antimicrobial activity. This peptide, consisting of 15 amino acids with + 3 net charges, was an effective antimicrobial agent against the on the Gram-positive strain, Staphylococcus aureus (MIC: $0.62{\mu}g/ml$). In addition, the hemolytic activity assay revealed that the peptide was not toxic to mouse and human erythrocytes up to $40{\mu}g/ml$. We also used circular dichroism spectroscopy to confirm that peptide in the presence of lipid has ${\alpha}-helical$ structures and later provide an overview of the relationship between each structure and antimicrobial activity. This peptide is a member of a new class of antimicrobial agents that could potentially overcome the problem of bacterial resistance caused by overuse of conventional antibiotics. Therefore, it could be used as a therapeutic or natural additive, particularly in the cosmetics industry.

• 대한수의학회지
• /
• 제21권2호
• /
• pp.161-165
• /
• 1981

A total of 210 dairy cows of Seongwhan area were epidemiologically investigated for mastitis by Milk Quality Test(MQT) method. Milk samples from cows infected with mastitis were also bacteriologically studied. Seventy four (42.5%) of 174 dairy cows were positive for mastitis and fifty nine (79.7%) among them were infected with subclinical mastitis and fifteen (20.3%) were clinical mastitis. High infective rate were shown on August (48.7%) and July (45.7%) and it was lowered on December (35.8%). The incidence rate of subclinical mastitis for herd shown tendency of increase at the barn in which located on lower place (30.7~43.9%), whereas, the barn in which was on higher place and with bucket type milking system shown tendency of decrease causative organisms. A total of 230 strains of etiological agents were isolated from 578 infected duarters which shown MQT score (+) or more. The relevant causative organisms isolated in this study were Staphylococcus aureus (18.3%), Staphylococcus epidermidis (16.9%), fungi (16.5%), Pseudomonas aeruginosa (15.2%), Escherichia coli (7.8%) and Serratia marcescens (2.27), respectively.