• Korean Journal of Clinical Laboratory Science
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• v.47 no.2
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• pp.65-70
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• 2015

Antimicrobial agents or additives have commonly been used in domestic animals for the prevention and treatment of bacterial diseases. Unfortunately, this has resulted in the overgrowth of bacteria that is resistant to antimicrobial agents used by humans, and these might get disseminated to humans via the food. In this study, we investigated the prevalence of integrons, and characterized gene cassette arrays in Proteus mirabilis isolates obtained from chickens in Chungcheong province of Korea. Additionally, the correlation between gene cassette arrays and antimicrobial resistance rate was studied. A total of 26 Proteus mirabilis isolates were recovered from chickens in Chungcheong province in Korea. Antimicrobial susceptibility was determined by disk diffusion method. PCR and DNA sequencing were performed to characterize the gene cassette arrays. In addition, we employed repetitive extragenic palindromic sequence-based PCR (REP-PCR) method for clonality analysis of P. mirabilis strains. Of the 26 P. mirabilis isolates tested, 14 (53.8%) isolates carried class 1 integrons, while class 2 and class 3 integrons were not detected in our study. The class 1 integrons harbored genes encoding resistance to aminoglycosides (aacCA5, aadA2, aadA5 and aadA7), trimethoprim (dfrA17, and dfrA32), lincosamides (linF) and erythromycin (ereA). In particular, the presence of class 1 integron had a significant correlatation to a high resistance rate of aminoglycoside and trimethoprim. We confirmed that class 1 integrons are widely disseminated in P. mirabilis isolates from chickens, contributing to the resistance to diverse antimicrobial agents in Korea. To prevent further spreading of antimicrobial resistant genes among P. mirabilis isolates, constant monitoring and clinical policing will become necessary.

• Korean Journal of Poultry Science
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• v.32 no.2
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• pp.101-106
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• 2005

This study was designed to estimate effect of wood vinegar on meat quality in old Layer which was low production and low economic value. The old layer chickens were used to resource for income increase of layer farm and protein supply. Two hundred forty Isa Brown chickens were assigned with control(Broiler feed), Treatment 1 (Broiler feed with addition of domestic wood vinegar $0.8\%$) and Treatment 2(Broiler feed with addition of foreign wood vinegar $0.4\%$). Feed intake of control group was lower 3g than other treatments. This is the reason of result that what organic acid in wood vinegar of treatment groups affect to feed digestibility, The different of chicken production was depended on ingredient and included value of wood vinegar in domestic and foreign. Foreign wood vinegar have organic acids which that functionally act sexual Pheromone so that promote endocrine matter. This is reason that old Layer chicken increase to egg production rate. Treatment 2 group effect to thigh meat rather than breast meat and improve to value of crude fat and meat color. The Meat quality and sensory test of thigh meat of foreign wood vinegar was better appraise rather than that of domestic wood vinegar. Because foreign wood vinegar make to fine of meat tissue and to decline cooking loss and also to increase juiciness and tenderness on sensory test.

• Korean Journal of Veterinary Research
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• v.23 no.2
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• pp.187-191
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• 1983

In the course of surveying the internal parasites of domestic animals, a large number of eggs and mites were detected in the feces and feeds of cattle, pigs, chickens and ducks. Three kinds of mites were identified in the present studies: Acarus siro (Linnaeus), Tyrophagus putrescentiae (Schrank) and Cheyletus malaccensis (Oudemans). The eggs of the mites were similar to those of flukes. In the fecal examination, therefore, it is necessary to differentiate the mite eggs from fluke eggs. The mites found in the present studies live by organic materials. Thus, they were found in the mixed commercial animal feeds. The spoiling of animal feeds by these mites remains to be verified. The damage of the gut epithelium of animals by these adult mites has to be examined more thoroughly, although macroscopic changes were not detected in the present studies. In the commercial animal feeds, the mites were largely found during the warm, humid seasons. As these mites can cause dermatitis in man, care should be taken not to contact continuously with the contaminated feeds.

• Korean Journal of Poultry Science
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• v.29 no.1
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• pp.59-75
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• 2002

The present study was conducted to compare the disease resistance to fowl typhoid among White Leghorn (WL) known as possessing greater genetic resistance to Salmonella, Rhode Island Red (RIR) susceptible to the disease and their mating crossbreed, WL ${\times}$RIR. Also, it was carried out to compare fowl typhoid-resistance among Hyline white${\times}$Hyline brown(HwHb), Hw${\times}$lsa brown(Hwlb), Isa white${\times}$lb(Iwlb), Iw${\times}$ Hb(IwHb) and Ib ${\times}$ Iw(IbIw) in order to select crossbreed chickens which have disease resistance to fowl typhoid and simultaneously produce the brown eggs which our domestic consummers prefer There was no death of WL chickens challenged with Sal. gallinarum at each 2, 5 and 8 wk of age, while average 86.2 to 64.1% of RIR chickens tested died at the same challenge age during the test period of 2 weeks. Their maiting crossbreed, WL ${\times}$ RIR were intermediate between the two breeds. weight gains of tested chickens were significantly higher in WL and WL ${\times}$RIR without difference between them than RIR. In recovery rate of tested strain of Sal. gallinarum from braun, heart, fiver, spleen and cecum of chickens challenged, WL ${\times}$RIR fell between the other two breeds, with somewhat higher rate then WL but much lower then RIR. In the disease resistance determination test using HwHb, Hwlb, Iwlb, IwHb and IbIw$.$ crossbreed chickens experimentally infected with Sal. gallinarum, it was recognized that all of crossbreeds tested developed marked resistance to fowl typhoid, based on the results judged by the measurement parameters of mortality, weight gain, recovery rate of challenged strain of bacteria, and positive rate of agglutination antibody, and HwHb had a tittle higher disease resistance then ethers.

• Journal of Microbiology
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• v.43 no.5
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• pp.424-429
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• 2005

In previous studies, it has been reported that both S. enteritidis, the most common serotype, and S. enteritidis Phage Type 4 (SEPT 4) isolates were identified as the most prevalent PT in domestic poultry and also in humans in Korea until 2002. The aim of this study was to analyze the genetic diversity and epidemiological properties of both PT isolates, and also to trace the source of SEPT 4 isolates from domestic poultry and humans by Pulsed-field gel electrophoresis (PFGE). In order to understand the molecular epidemiologic properties of SEPT 4 isolates, which have very similar phenotypic properties to our preliminary investigations (serotyping, phage typing, large plasmids and antibiograms), PFGE analysis with XbaI enzyme was performed on the representative SEPT 4 isolates. Thirty-six SEPT 4 isolates were analyzed and differentiated with 10 pulsed-field profiles (PFP) expressing very high discriminative ability (SID: 0.921). In PFP, SEPT 4 isolates from human patients showed a perfect genetic match with those from broiler chickens and meats. Therefore, this study was able to successfully trace the major source of SEPT 4 isolates and also to determine the usefulness of the PFGE method for genetic analysis of epidemic strains.

• Korean Journal of Organic Agriculture
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• v.17 no.4
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• pp.539-555
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• 2009

The potential of encapsulated inuloprebiotics from domestic Jerusalem artichokes (Helianthustuberosus) as natural antibacterial growth promotor for an antibiotic replacement in broiler chickens was presently assessed through assays of growth performance, serum immunoglobulin production and influence on caecal microflora. Two hundred-forty, 1-day-old, male broilers (Ross 308) were randomly allotted to four treatments (T1-T4), with three replicate pens per treatment and 20 chicks per pen. Broiler chicks were fed a basal diet (T1: control) or basal diet plus antibiotics (T2: Chlorotetracycline, 0.10%), 300 ppm of the inuloprebiotics (T3), or 450 ppm of the inuloprebiotics (T4) for 35 days. Body weight, dressing percentage or weight of breast and thigh muscles relative to carcass weight of T3 and T4 broiler chickens was significantly (P<0.05) higher than T1 and T2 broiler chickens. The weight of abdominal fat from T3 and T4 broiler chickens were significantly (P<0.05) lower than that of T1 and T2 chickens. Serum immunoglobulins in the T3 and T4 groups were significantly (P<0.05) elevated compared to the T1 and T2 groups. The weight of immune organs, thymus and Bursa of Fabricius relative to live body weight in the T3 and T4 groups were significantly (P<0.05) higher than the T1 and T2 groups. Bifidobacteria and Lactobacillus, which are beneficial bacteria, were present in greater numbers in the caecum of T3 and T4 birds than T1 and T2 groups, whereas potentially harmful Escherichiacoli and Salmonella were present in lower numbers, with differences being significant (P<0.05). These results suggest that a diet supplemented with 300 ppm of inuloprebiotics has potential as an antibiotic replacement for organic livestock feed supplement intended to improve production of broiler chicken.

• Korean Journal of Veterinary Service
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• v.24 no.1
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• pp.51-68
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• 2001

The result of studying the epidemiological characteristics of Salmonella strains which have been isolated from the domestic animals in Gyeongbuk province from February 1998 to August 2000 were summarized as follows. The isolation rates of Salmonella strains were 2.0% from cattle feces, 6.3% from cattle lymph node, 9.5% from pig feces, and 25.1% from pig lymph node. In poultry, the isolation rates were 30.3%. The isolates of Salmonella showed positive reaction for MUCAP test, methyl red test, but showed negative reaction for urea test, indole test, Voges Proskauer test. On TSI agar, the isolates showed acid butt, alkaline slant. Also, the isolates were identified as Salmonella strain by API 20E kit. Non H$_2$S Production Salmonella strains isolated from poultry were identified as S gallinarum. As a result of serotyping, B group were the most common in cattle and pig, Dl in chickens. 21 serovars were found. the common serovar from the domestic animals was S typhimurium, S derby, S agona, S schwarzenground, S enteritidis and S gallinarum. The most commonly encountered serovars in cattle were S agona and S typhirimurium in pig, S gallinarum in chicken. As a result of antimicrobial susceptibility test, all Salmonella isolates were susceptible to amikacin, ciprofloxacin, norfloxacin; cefotaxime and polumcin B. The resistance rates to tetracycline and streptomycin was 58% and 56%, respectively. 69.3% of all isolates were resistant to more than one antimicrobial agent. Out of the resistant isolates, the isolates resistant to streptomycin and tetracycline was 36%. There were 24 strains of multiresistant isolates resistant to more than 5 antimicrobial agents. S typhimurium were resistant to all antimicrobial agents, also had a lot of multiresistant strains. Therefore, S typhimurium was considered as a major agent of antimicrobial resistance.

• Journal of Animal Science and Technology
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• v.55 no.2
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• pp.103-107
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• 2013

A crucial first step in the planning of any scientific experiment is to evaluate an appropriate sample size to permit sufficient statistical power to detect the desired effect. In this study, we investigated the optimal sample size of quantitative trait locus (QTL) linkage analysis for simple random sibship samples in pedigreed chicken populations, under the variance component framework implemented in the genetic power calculator program. Using the program, we could compute the statistical power required to achieve given sample sizes in variance component linkage analysis in random sibship data. For simplicity, an additive model was taken into account. Power calculations were performed to relate sample size to heritability attributable to a QTL. Under the various assumptions, comparative power curves indicated that the power to detect QTL with the variance component method is highly affected by a function of the effect size of QTL. Hence, more power can be achievable for QTL with a larger effect. In addition, a marked improvement in power could be obtained by increasing the sibship size. Thus, the use of chickens is advantageous regarding the sampling unit issue, since desirable sibship size can be easily obtained compared with other domestic species.

• Korean Journal of Poultry Science
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• v.42 no.2
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• pp.157-167
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• 2015

We compared the degrees of stress response of 12 domestic purebred chicken strains that have been bred at National Institute of Animal Science, RDA, Korea since 1980. As a physiological marker of stress response, the expression levels of heat shock protein (HSP)-70, HSP-$90{\alpha}$, HSP-$90{\beta}$, hydroxyl-3-methyl-glutaryl coenzyme A reductase (HMGCR) genes and telomere length were measured by quantitative real-time polymerase chain reaction using the lymphocytes of 1,101 chickens. There was significant difference in HSP-70, HSP-$90{\alpha}$, HMGCR expression and telomere length among the strains. There was also significant difference in HSP-$90{\alpha}$, HSP-$90{\beta}$, and HMGCR expression between male and female chickens. Different age groups of chicken exhibited different expression levels of HSP-70, HSP-$90{\alpha}$ and telomere length. The results of the HSPs expression level suggested that, the strains of R, L and Y were highly resistant to stress, whereas the strains of S, O and W were susceptible to stress. Although the statistical differences in some of HSPs gene expression existed between genders, the HSP expression results varied in different strains that some opposed to the others, and there might be interaction between strains and genders, which conclude that there was no difference in stress response between male and female chickens. Moreover, despite of significant difference in some of HSPs expression level, it was considered that there was no difference in stress response between ages due to the inconsistent trends among HSP markers.

• Journal of Life Science
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• v.31 no.12
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• pp.1079-1087
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• 2021

To analyze gut microbiota of livestock in Korea and compare taxonomic differences, we conducted 16S rRNA metagenomic analysis through next-generation sequencing. Fecal samples from broiler chickens, pigs, and cattle were collected from domestic feedlots randomly. α-diversity results showed that significant differences in estimated species richness estimates (Chao1 and ACE, Abundance-based coverage estimators) and species richness index (OUTs, Operational taxonomic units) were identified among the three groups. However, NPShannon, Shannon, and Simpson indices revealed that abundance and evenness of the species were statistically significant only for poultry (broiler chickens) and mammals (pigs and cattle). Firmicutes was the most predominant phylum in the three groups of fecal samples. Linear discriminant (LDA) effect size (LEfSe) analysis was conducted to reveal the ranking order of abundant taxa in each of the fecal samples. A size-effect over 2.0 on the logarithmic LDA score was used as a discriminative functional biomarker. As shown by the fecal analysis at the genus level, broiler chickens were characterized by the presence of Weissella and Lactobacillus, as well as pigs were characterized by the presence of provetella and cattele were characterized by the presence of Acinetobacter. A permutational multivariate analysis of variance (PERMANOVA) showed that differences of microbial clusters among three groups were significant at the confidence level. (p=0.001). This study provides basic data that could be useful in future research on microorganisms associated with performance growth, as well as in studies on the livestock gut microbiome to increase productivity in the domestic livestock industry.