• IMMUNE NETWORK
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• v.15 no.1
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• pp.27-36
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• 2015

In the present study, we investigated the protection conferred by a live attenuated Salmonella enterica serovar Typhimurium (ST) strain against Salmonella Typhimurium, Salmonella Gallinarum (SG), and Salmonella Enteritidis (SE) infection in layer chickens. Birds were orally primed with the attenuated ST strain at 7 days of age and then boosted at 4 weeks post prime immunization (PPI). Sequential monitoring of plasma IgG and mucosal secretory IgA (sIgA) levels revealed that inoculation with ST induced a significant antibody response to antigens against ST, SE, and SG. Moreover, significant lymphoproliferative responses to the 3 Salmonella serovars were observed in the immunized group. We also investigated protection against virulent ST, SE, and SG strain challenge. Upon virulent SG challenge, the immunized group showed significantly reduced mortality compared to the non-immunized group. The reduced persistence of the virulent ST and SE challenge strains in the liver, spleen, and cecal tissues of the immunized group suggests that immunization with the attenuated ST strain may not only protect against ST infection but can also confer cross protection against SE and SG infection.

• Journal of Veterinary Science
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• v.23 no.5
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• pp.64.1-64.9
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• 2022

Background: Fluralaner is a novel drug belonging to the isoxazoline class that acts on external parasites of domestic animals. It is used systemically via drinking water, especially against red poultry mite in layer chickens. Fluralaner is frequently used in layers infected with D. gallinae. However, no study to date has investigated the effects of feed intake and water hardness. Objectives: This study aimed to investigate the effects of variable water hardness and feed intake on the pharmacokinetic profile of fluralaner. Methods: Layer chickens were divided into four groups (n = 8): fed + purified water (Group 1), feed restricted + purified water (Group 2), feed restricted + hard water (Group 3), and feed restricted + soft water (Group 4). After administering a single dose of the drug with drinking water, the blood samples were collected for 21 days. Fluralaner concentrations in plasma samples were determined by liquid chromatography/tandem mass spectrometry. The maximum plasma concentration (C_max), time to reach maximum plasma concentration (t_max), area under the concentration-time curve values (AUC_0-21d), half-life (t_1/2), and other pharmacokinetic parameters were calculated. Results: Although the highest maximum plasma concentration (C_max) was determined in Group 1 (fed + purified water), no statistically significant difference was found in the C_max, t_max, t_1/2, MRT_{0-inf_obs}, Vz/F_obs, and Cl/F_{_obs} parameters between the experimental groups. Conclusions: It was concluded that the feed intake or water hardness did not change the pharmacokinetic profile of fluralaner in layer chickens. Therefore, fluralaner could be used before or after feeding with the varying water hardness in poultry industry.

• Korean Journal of Veterinary Research
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• v.31 no.4
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• pp.471-477
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• 1991

Attempts to isolate chicken anemia agent (CAA) were made by inoculating tissue homogenates into MDCC-MSBl or LSCC-1104B1 cell lines and passaging the cells serially. CAA was isolated from the liver and thymus of 11 weeks old layer chickens and from the liver of 10 weeks old broiler breeder chickens. The layer flock experienced approximately 45% mortality during 9 to 14 week of age from gangrenous dermatitis and lymphoid organs of affected chickens were severely atrophied. The broiler breeder flock experienced approximately 7% mortality during 7 to 9 weeks of age and affected birds showed lesions of colibacillosis, staphylococcal arthritis, and coccidiosis together with atrophied lymphoid organs. The isolated viruses were identified as CAA by the indirect fluorescent antibody test and virus neutralization test using CAA immune sera including one to Gifu-1 strain of CAA. The CAA isolate 89-69, when inoculated into susceptible 1 day old SPF chicks, induced anemia 14 to 16 days after inoculation. It did not induce any cytopathic effects in chicken embryo liver and chicken embryo fibroblast cell cultures. Infectivity of the isolate was not affected by the treatment of chloroform or heat ($70^{\circ}C$ for 15 minutes).

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.7
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• pp.974-980
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• 2014

In semi-arid areas of Southern Africa, dehydration can compromise the performance and welfare of local chickens, particularly during the growing period when confinement is curtailed and birds are left to scavenge for feed and water. The effect of water restriction on the growth performance was compared in Naked Neck (NNK) and Ovambo (OVB) chickens that are predominant in Southern Africa. A total of 54 eight-wk-old pullets each of NNK and OVB chickens with an initial average weight of $641{\pm}10g/bird$ were randomly assigned to three water intake treatments, each having six birds for 8 wk. The water restriction treatments were ad libitum, 70% of ad libitum and 40% of ad libitum intake. Nine experimental pens with a floor space of $3.3m^2$ per strain were used. The pens were housed in an open-sided house with cement floor deep littered with a 20 cm layer of untreated wood shavings. Feed was provided ad libitum. Average daily water intake (ADWI), BW at 16 weeks of age (FBW), ADG, ADFI, feed conversion ratio (FCR) and water to feed ratios (WFR) were determined. Ovambo chickens had superior (p<0.05) FBW, ADG and ADWI than NNK chickens. Body weight of birds at 16 weeks of age, ADG, ADFI, ADWI, and WFR declined progressively (p<0.05) with increasing severity of water restriction while FCR values increased (p<0.05) as the severity of water restriction increased. Naked Neck chickens had better FCR at the 40% of ad libitum water intake level than Ovambo chickens. The dressing percentage per bird was higher in water restricted birds than those on ad libitum water consumption, irrespective of strain. Heart weight was significantly lower in birds on 40% of ad libitum water intake than those on ad libitum and 70% of ad libitum water intake, respectively. In conclusion, NNK chickens performed better than OVB chickens under conditions of water restriction and would be ideal to raise for meat and egg production in locations where water shortages are a major challenge.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.7
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• pp.1037-1047
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• 2017

Objective: Despite an increasing number of investigations into the pathophysiology of necrotic enteritis (NE) disease, etiology of NE-associated diseases, and gene expression profiling of NE-affected tissues, the microRNA (miRNA) profiles of NE-affected poultry have been poorly studied. The aim of this study was to induce NE disease in the genetically disparate Fayoumi chicken lines, and to perform non-coding RNA sequencing in the intestinal mucosal layer. Methods: NE disease was induced in the Fayoumi chicken lines (M5.1 and M15.2), and non-coding RNA sequencing was performed in the intestinal mucosal layer of both NE-affected and uninfected chickens to examine the differential expression of miRNAs. Next, quantitative real-time polymerase chain reaction (real-time qPCR) was performed to further examine four miRNAs that showed the highest fold differences. Finally, bioinformatics analyses were performed to examine the four miRNAs target genes involvement in the signaling pathways, and to examine their interaction. Results: According to non-coding RNA sequencing, total 50 upregulated miRNAs and 26 downregulated miRNAs were detected in the NE-induced M5.1 chickens. While 32 upregulated miRNAs and 11 downregulated miRNAs were detected in the NE-induced M15.2 chickens. Results of real-time qPCR analysis on the four miRNAs (gga-miR-9-5p, gga-miR-20b-5p, ggamiR-196-5p, and gga-let-7d) were mostly correlated with the results of RNAseq. Overall, ggamiR-20b-5p was significantly downregulated in the NE-induced M5.1 chickens and this was associated with the upregulation of its top-ranking target gene, mitogen-activated protein kinase, kinase 2. Further bioinformatics analyses revealed that 45 of the gene targets of gga-miR-20b-5p were involved in signal transduction and immune system-related pathways, and 35 of these targets were predicted to interact with each other. Conclusion: Our study is a novel report of miRNA expression in Fayoumi chickens, and could be very useful in understanding the role of differentially expressed miRNAs in a NE disease model.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.5
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• pp.603-609
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• 2011

Telomeres are special structures at the ends of eukaryotic chromosomes. Vertebrate telomeres consist of tandem repeats of conserved TTAGGG sequence and associated proteins. Birds are interesting models for molecular studies on aging and cellular senescence because of their slow aging rates and longer life spans for their body size. In this longitudinal study, we explored the possibility of using telomeres as an age-marker to predict age in Single Comb White Leghorn layer chickens. We quantified the relative amount of telomeric DNA in isolated peripheral blood lymphocytes by the Quantitative Fluorescence in situ Hybridization technique on interphase nuclei (IQ FISH) using telomere-specific DNA probes. We found that the amount of telomeric DNA (ATD) reduced significantly with an increase in chronological age of the chicken. Especially, the telomere shortening rates are greatly increased in growing individuals compared to laying and old-aged individuals. Therefore, using the ATD values obtained by IQ FISH we established the possibility of age prediction in chickens based on the telomere theory of aging. By regression analysis of the ATD values at each age interval, we formulated an equation to predict the age of chickens. In conclusion, the telomeric DNA values by IQ FISH analyses can be used as an effective age-marker in predicting the chronological age of chickens. The study has implications in the breeding and population genetics of poultry, especially the reproductive potential.

• Korean Journal of Veterinary Service
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• v.19 no.3
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• pp.221-226
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• 1996

IBD's antibody level and morphological change of immune organ was examined in chicken. The results were as follows ; 1. Seventy percent at 42 day and 40% at 45 day of age chickens were reacted positively by the agar gel immunodiffusion test and 42 day and 45 day of age chickens indicated 1859, 1425 by the ELISA test, respectively. 2. In 2 and 5 day young broiler chickens, the level of maternal antibody was not proper. B/B ratio showed low level, but S/B ratio and BS were normal. 3. In layer, 100% of 8 and 86 day of age chicken and 70% at 40 day of age chicken had antibody aganist IBDV. The level of antibody was high as 2293 and 3336 in 8 and 86 day of age chicken, while was low as 1186 in 40 day of age chicken. B/B ratio showed low level and S/B ratio high level, but BS was normal.

• Korean Journal of Veterinary Pathology
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• v.7 no.1
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• pp.67-69
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• 2003

Three mature layer chickens from a farm in which chickens showed green diarrhea, cyanosis, lethargy, loss of appetite were pathologically examined. Grossly, multiple variable sized caseous nodules were detected in the liver, intestinal serosa and mesentery. In addition, parathypoid nodules in the liver and fibrous serositis on the several peritoneal organs and tissues were noticed. One of spleens had multiple infarction areas. Histologically caseous nodules consisted of central caseous core and peripheral epithelioid cells overlying the fibrous connective tissue. Multinucleated giant cells were scattered between the epithelioid cells and fibrous connective tissue. In these nodules Gram negative cocobacilus bacterial colonies were present, whereas Periodic Schiff reaction and Ziehl-Neelsen stain detected neither fungi nor acid fast bacteria. From these results multiple granulomas might be induced by Escherichia coli. In addition, severe Ascafdiodf and Salmonellosis were coinfected in these chickens.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.10
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• pp.1369-1378
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• 2006

This is the first study in which genetic variability and relationships of a large number of Japanese chicken breeds were revealed along with those of several foreign breeds by using microsatellite DNA polymorphisms. Twenty-eight breeds (34 populations) of native Japanese chickens and seven foreign breeds or varieties were analyzed. The mean number of alleles per locus, the proportion of the polymorphic loci, and the expected average heterozygosity ranged from 1.75 to 4.70, from 0.55 to 1.00, and from 0.21 to 0.67, respectively. Microsatellite alleles being unique to a particular population were detected in some populations. The $D_A$ genetic distance between populations was obtained from allele frequency for every pair of the populations to construct a neighbor-joining tree. According to the phylogenetic tree, excluding a few exceptions, native Japanese chicken breeds and foreign breeds were clearly separated from each other. Furthermore, the tree topology divided native Japanese chickens into four main classes, which was almost in accordance with the classification based on body morphology; that is, (1) Cochin type, (2) Malay type, (3) layer type, and (4) intermediate type between Malay and layer types. This is the first finding for native Japanese chickens.

• Korean Journal of Veterinary Research
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• v.37 no.3
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• pp.569-576
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• 1997

Fowl typhoid(FT) caused by Salmonella gallinarum is an infectious, egg-transmitted disease and characterized by swollen bronze liver, greenish-yellow diarrhea and high mortality in growing and adult chickens. Since 1992 the outbreak of FT has been increased. Several problems have been occurred such as absence of appropriate vaccines and lack of useful therapeutic methods. In these studies we investigated the pathogenicity of S gallinarum isolated in chickens. To compare the pathogenicity among the species of chickens, all chickens were challenged intramuscularly or orally with $1{\times}10^7$ CFU of S gallinarum. The brown-colored layers were more susceptible and white leghone chickens were more resistant than other species. In the brown layer chickens orally challenged, lethal doses ($LD_{50}$) of the isolates were inoculated at 1 day, 2 weeks, 4 weeks and 8 weeks old chickens with amount of $10^{4.2}$, $10^{4.7}$, $10^{7.0}$ and $10^{7.6}$ CFU, respectively. The chickens which were intramuscularly challenged with the less amount than $10^2$ CFU showed higher mortality than that of the chickens orally inoculated with same dose. Also, we investigated the recovery rates of bacteria from various organs of survival chickens which were challenged orally with $5{\times}l0^7$ CFU of S gallinarum. The bacteria was more frequently and isolated earlier from the liver and spleen than from any other ogans. In the pathogenicity test, the white-leghorn chickens which were known as resistant-strain against Salmonella were artificially immunosuppressed using bursectomy and/or dexamethasone treatment. Mortality of chickens with both bursectomized and treated with dexamethasone was higher(90%) than that of the control group(10%), the bursectomized chickens(10%) and the dexamethasone only treated group(20%). It was suggested that the protective mechanism in chickens against S gallinarum may be required both the functions of B-cells and T-cells.