• 한국동물위생학회지
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• 제31권1호
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• pp.129-135
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• 2008

A total of 3,943 samples (beef 698, pork 2,178 and chicken 1,067)were collected from slaughter houses in Daegu from January to December 2006 for analysis of antimicrobial residues. The results were also comparatively analyzed with those carried out from 16 veterinary service laboratories nationwide as a part of national residue program in 2006. The samples from 11 farms (cattle 2, pig 9) were found to exceed the legal limit. Among them 5 were classified as tetracyclines, 3 as $\beta$-lactams, 2 as sulfonamides and 1 as quinolone. Nationally a total of 222 farms (241 cases) were found to violate the residual limits, of which 47.3% were detected by screening test, followed by surveillance (38.3%). Failure to observe withholding periods of antimicrobial drugs after treatment was the most significant cause of the non-compliance.

• 한국동물위생학회지
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• 제31권1호
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• pp.43-55
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• 2008

Recently, the major viral diseases, Newcastle disease (ND), infectious bronchitis (IB), low pathogenic avian influenza (LPAI), avian pneumovirus infection (APV), Marek's disease (MD) and infectious bursal disease (IBD), have led to huge economic losses in chicken industry of Korea. To evaluate prevalence of the major viral disease infections in broiler breeder and broiler farms, epidemiological survey has been conducted in Jeonbuk province from 2005 to 2007 by serological ELISA test for APV, PCR for MD, and RT-PCR for ND, IB, LPAI and IBD, respectively. A total of 424 cases was submitted to our laboratory for diagnosis of the major viral disease from broiler breeder and broiler farms in the above period. The diagnosed results were analysed for the detection rate of infections on basis of years, seasons and ages, respectively. This study was showed that the detection rates of ND and APV were considerably high for every years regardless of seasons and ages in both broiler breeder and commercial broiler. In comparison with detection rates of ND and APV, IB and LPAI were lower but detected around 10% for every years. Especially, detection rate of IB was significantly high in commercial broiler than in broiler breeder. Therefore, to minimize economic losses for broiler breeder and broiler farms, it will need for effective countermeasures to decrease detection rate of the viral respiratory diseases. Although the detection rates of MD and IBD were gradually decreased from 2005 to 2007 in both broiler breeder and commercial broiler, it will continually make an effort about disease control for increasing productivity in chicken industry.

• 한국축산시설환경학회지
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• 제3권1호
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• pp.49-56
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• 1997

Most of Korean broiler farms are constructed with vinyl houses. Such types of broiler farms might be cheaper in terms of cost, but poor in terms of environment condition. According to enlargement of broiler farm size, high value production systems or automatic facilities are introduced in this field. However, investment may not always guarantee the profit of the management. Therefore, it is necessary to undertake the investment analysis before decision making for the investment. Under the assumption that 870 Pyoung(≒$3.3㎡) of a broiler farm within 1,740 Pyoung(≒3.3㎡) of land is built with the producing capacity of 50,000 heads of chicken in a time. The total investment is calculated to be 600 million won(1,000 won≒$1.1), and out of them 58.1% is provided by the owner, 31.6% from the government loan, 5.8% from government subsidy, and 5.3% from other agencies or banks. The expected profit of the broiler farm is 64.6 million won(1,000 won≒$1.1) per year. The IRR calculated is 0.0808 which means that the rate to profit of this project would be 8.1%. This also means that for this investment the interest rate of the capital provided should be less than 8.1% per year. Considering that the current opportunity cost of the own capital is 8.5% this project is not so attractive for those who is going to build broiler farms mainly with their own capital. In other words this project would not be profitable, unless the average interest rate of the loans provided for this project is less than 8.1% per year.

• 한국가금학회지
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• 제46권4호
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• pp.249-253
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• 2019

닭 마이코플라즈마병은 전세계적으로 양계산업에 문제시 되고 있는 난계대 질병으로 병아리 품질 및 사육성적에 영향을 미친다고 알려져 있다. 본 연구는 닭 마이코플라즈마병에 대한 백신 접종을 실시하지 않은 계열화 회사의 육용 종계군을 대상으로 정기 채혈을 통해 혈청검사를 실시한 후 감염율을 확인하였고, 조사계군에서 생산된 육계 병아리에 대한 사육성적을 확인하고자 하였다. 육용종계 닭 마이코플라즈마 감염율과 그에 따른 후대병아리의 사육성적을 연도별로 확인한 결과, 종계군의 감염율이 낮아짐에 육계의 사육성적이 높아진다는 상관관계를 확인하였다. 이러한 결과를 토대로 비추어 보았을 때, 닭 마이코플라즈마병의 감염 유무는 생산된 초생추의 품질과 사육농장 성적 영향에 미치는 여러 요소들 중 하나라고 판단할 수 있다.

• 한국동물위생학회지
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• 제33권1호
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• pp.45-50
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• 2010

Mycoplasma gallisepticum (MG) is major cause of chronic respiratory disease in chickens. M. synoviae (MS) most frequently occurs a subclinical upper respiratory infection but may result in airsacculitis and synovitis in chickens and turkeys. Both mycoplasmas induce economic losses by triggering chronic respiratory signs, airsacculitis and decreased egg production. For prevention of the infections, live attenuated andinactivated vaccines are commercially used for prevention of MG but not MS in Korea. Serum plate agglutination (SPA) and enzyme-linked immunosorbent assay (ELISA) have been commonly used for serological diagnosis for MG and MS. Recently, it is believed that MS spread in chickens is very seriously in Korea and respiratory infection with MS causes substantial loss in poultry farms. In this study, we investigated the serological prevalence of MG and MS in unvaccinated chickens between 2008 and 2009. The overall seroprevalence of MG was 24% of 2,094 for individual chickens and 24% of 189 farms. The overall seroprevalence of MS was 36% in 2,095 chickens and 39% in 198 farms. The results show that seropositive ratio of MS is higher than MG. The geographical prevalence of MG has been estimated in following sequence; Gangwon, Jeolla, Gyeonggi, Gyeongsang, and Chungcheong. The geographical prevalence of MS has been estimated as follows; Gangwon, Gyeonggi, Gyeongsang, Chungcheong, and Jeolla. Seasonal seroprevalencewas also examined, and it found that seroprevalence in spring, fall and winter was higher than that in summer in MG, but not in MS. No significant difference was shown in seroprevalence according to breed. Future study about pathogenicity of MS isolates would be needed and economical losses by MS outbreaks should be analyzed. Moreover, we compared sero-positivity obtained with SPA and ELISA. The kappa value of MG between SPA and ELISA was 0.8061 and the kappa value of MS between SPA and ELISA was 0.7649.

• 한국가금학회지
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• 제47권2호
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• pp.115-119
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• 2020

Fowl cholera is an infectious disease caused by Pasteurella multocida that contributes to high economic loss in the commercial chicken industry. Three Pasteurella multocida strains were isolated from outbreaks of acute fowl cholera in the Korean layer farms from 2018 to 2019. One strain was identified and serotyped using capsular PCR typing. This strain was also genotyped by lipopolysaccharide (LPS) PCR typing as A: L3, whereas other strains were non-typable. The multilocus sequence typing (MLST) result showed that the A: L3 strain is sequence type (ST) 134; the non-typable strains were recorded as the following new STs: ST 366 and ST 374. Using phylogenetic tree analysis based on MLST sequences, we determined that ST 366 and ST 374 are closely related to the reference strains that were previously isolated from duck and chicken in Korea, and they were highly prevalent within the Korean cluster. In conclusion, Pasteurella multocida strains were identified and isolated in this study. Furthermore, this is the first report of using MLST to determine the prevalence of fowl cholera in Korea.

• 한국임상수의학회지
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• 제19권2호
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• pp.159-164
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• 2002

The present study was conducted to investigate the antibiotic resistance of 24 Salmonella gallinarum isolated from 48 chicken samples of diagnosed fowl typhoid cases during the period from November 1998 to November 1999. And the isolates of S gallinarum were also tested for their invasion abilities to experimental infection as one of virulence tests, and the presence of virulence-related plasmid in S gallinarum isolates. The results obtained through this study were summarized as follows; 1. All of isolates from 48 cases of 24 farms were identified S gallinarum by biochemical and serological tests.2. Antimicrobial drug resistance test against 24 isolates showed that the isolates were resistant to Colistin(95.8%), and Penicillin(79.2%), Polymyxin B(75.0%), Streptomycin (65.2%), Gentamycin(54.2%), and Tetracycline(33.3%). 3. Mortality in chicken following peroral inoculation of four isolates of S gallinarum during 14-days inoculation pecked at 5 days(40%) after inoculation and all of experimental chickens died within 13 days after inoculation.4. Based on the pattern and number of isolated plasmid from each isolate, plasmid profiles were divided into five groups; group I with 3 plasmids, group II to group IV with 4 plasmids and group V with 5 plasmids.

• 한국가금학회지
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• 제38권2호
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• pp.155-164
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• 2011

The use of antimicrobials will be soon removed due to an increase of occurrence of antibiotic-resistant bacteria or ionophore-resistant Eimeria species in poultry farms and consumers' preference on drug-free chicken meats or eggs. Although dietary antimicrobials contributed to the growth and health of the chickens, we do not fully understand their interrelationship among antimicrobials, gut microbiota, and host immunity in poultry. In this review, we explored the current understanding on the effects of antimicrobials on gut microbiota and immune systems of chickens. Based on the published literatures, it is clear that antibiotics and antibiotic ionophores, when used singly or in combination could influence gut microbiota. However, antimicrobial effect on gut microbiota varied depending on the samples (e.g., gut locations, digesta vs. mucosa) used and among the experiments. It was noted that the digesta vs. the mucosa is the preferred sample with the results of no change, increase, or decrease in gut microbiota community. In future, the mucosa-associated bacteria should be targeted as they are known to closely interact with the host immune system and pathogen control. Although limited, dietary antimicrobials are known to modulate humoral and cell-mediated immunities. Ironically, the evidence is increasing that dietary antimicrobials may play an important role in triggering enteric disease such as gangrenous dermatitis, a devastating disease in poultry industry. Future work should be done to unravel our understanding on the complex interaction of host-pathogen-microbiota-antimicrobials in poultry.

• 한국동물위생학회지
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• 제18권2호
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• pp.113-123
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• 1995

The present study was conducted to investigate the prevalent characteristics of Fowl Typhoid and antibiotic susceptibility of Salmonella gallinarum isolated from 56 infective or dead chickens of 20 egg laying farms in Kyung Buk province during the period from August to December 1994. 1. Among 416, 000 chickens of 92 flocks in 20 egg laying farms, 17, 360 chickens of 31 flocks were died of Fowl Typhoid. 2. Salmonella gallinarum was isolated from 56 chickens in liver and spleen, and then blood of infective chickens was positive to Pullorum antigen. 3, In the survey of gross lesion of 56 chickens, 43 chickens(76.8%) were swelled at liver, 39(69.6%) were swelled at spleen, 12(21.4%) were changed with bronze, 3(5.4% ) were hemorrhagic in peritoneal cavity. 4. In transmission pattern, 4 farms were outbreaked the entrance of chicken house at first, but the others were outbreaked at various place. They were transmitted at right and left directions in flock. 5. 2 farms confirmed at the early stage of infection were eradicated by removing infective chickens and administrating antibiotics, but 18 farms at chronic stage were not. 6. The biochemical properties of 112 Salmonella gallinarum from chickens were generally identical to those of the referance, but H$_2$S was not productive, cellobiose was fermentive. 7 Minimum inhibitory concentration(MIC) of 20 isolates was performed by using 21 antibiotics, MICs of Amikacin(Ak), Gentamicin(Gm), Kanamycin(Km), and Tetracycline (Tc) were below 1.6 ug/ml, Ampicillin(Am), Furazolidone(Fu) and Neomycin(Nm) were below 3.1 ug/ml, Cephalothin(Ce), Cefazoline(Cf) and Chloramphenicol(Cm) were below 6.3 ug/ml, Nalidixic acid(Na), Polymyxin(Po) and Rifampicin(Rf) were below 12.5 ug/ml, Penicillin (Pm) was below 25 ug/ml, Colistin(Co) and Streptomycin(Sm) were below 50 ug/ml, Sulfamerazine(Sr) and Sulfamethazine (St) were below 200 ug/ml, Lincomycin(Lm) and Spiramycin(Sp) were below 400 ug/ml, Bacitracin(Ba) was below 800 ug/ml. 8. Among the 20 isolates, all(100%) of those were sensitive to Ak, Am, Ce, Cf, Cm, Fu, Gm, Km, Na, Nm, Po, Rf, Sr, St and Tc, but 6 isolates(30%) were resistent to Co, 20(100% ) to Ba, Lm, Pm, Sm, and Sp. The drug resistance patterns were simple which 6 strains were BaCoLmPmSmSp type, and 14 were BaLmPmSmSp type.

• 한국가금학회지
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• 제48권4호
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• pp.239-253
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• 2021

본 연구는 Cobb종 및 Ross 308종 육계가 동물복지 사육환경에 따라 나타내는 대사체학적 변화를 연구하기 위하여 수행되었다. 일반농장과 동물복지농장(사육면적, 사육밀도, 암모니아 농도, 볏짚 등 제공)에 1일령의 Cobb종 및 Ross종 육계를 35일간 사육하고, 도계 후 가슴육과 다리육을 채취하여 분석에 이용하였다. 대사체 분석은 one-dimensional ¹H 핵자기공명분광법을 이용하였고, 직교부분최소자승판별분석(OPLS-DA)과 대사경로 분석을 함께 수행하였다. OPLS-DA 결과 육계 가슴육은 Ross종에 한하여 사육농장간 뚜렷한 구분이 가능하였다. 동물복지농장 유래 Ross종 육계 가슴육은 acetate, anserine, creatine, inosine monophosphate 함량이 일반농장 닭가슴육에 비해 유의적으로 높았다(P<0.05). 반면 육계 다리육은 OPLS-DA 결과 Cobb종 육계에서만 사육농장에 따른 구분이 뚜렷하게 나타났는데, glucose와 lactate를 포함한 5종의 대사체 함량은 동물복지농장에서 사육된 경우에 높았으나 7종의 유리아미노산을 포함한 9종의 대사체 함량은 낮았다(P<0.05). 대사경로 분석 결과 Ross종 육계 가슴육에서는 4종, Cobb종 육계 다리육에서는 glycolysis/gluconeogenesis를 포함한 20종의 대사경로에서 사육농장 간 유의적인 차이(P<0.05)가 나타났다. 동물복지농장에서 사육된 Ross종 육계 가슴육과 Cobb종 육계 다리육은 일반농장에서 사육된 경우와는 다른 대사체학적 특성을 나타냈으며, 특히 풍미 물질에의 뚜렷한 차이를 보여 관능적 특성에 영향을 미칠 수 있으리라 사료된다.