• 한국동물위생학회지
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• 제22권4호
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• pp.385-392
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• 1999

A total of 420 chicken sera from various regions were tested for the presence of antibodies to avian rotavirus using indirect immunofluorescence assay (IFA). In broiler farms, rotavirus antibodies were detected from 20 farms among 30 farms tested and the positive rates were above 50% in 9 farms. In parent stock farms, rotavirus antibodies were detected from 5 farms among 14 farms tested. From sera collected in 7 layer farms rotavirus antibodies were not detected.

• 한국수정란이식학회지
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• 제30권2호
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• pp.115-119
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• 2015

The study was carried out to assess the production performances of Japanese quail parent stock raised under open housing system and the study was conducted in a local farm with 2000 Japanese parent stock quail birds (Coturnix coturnix japonica). Observed body weight gain was recorded in each weekend up to 7 weeks of their age; birds gained weight 15.73, 31.45, 47.20, 90.80, 125.27, 153.14 and 175.20 grams, respectively. There have been observed sharp decline of fertility and hatchability of birds with increase of their age. Optimum fertility was recorded at third week and optimum hatchability at fifth week of their age. Average flock uniformity was found 83.68%. The hen day egg production of the flock was recorded 81, 83, 85, 86, 89, 89, 89, 89 and 88% in each weekend, respectively. It may therefore be concluded that Japanese quail parent stock performs well under open housing system in Bangladesh and future study can be taken to better understand their production performances.

• 한국가금학회지
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• 제49권4호
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• pp.239-246
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• 2022

본 연구는 여름철 γ-aminobutyric(GABA)와 생균제 급여가 산란 종계의 생산성, 계란품질, 혈액 생화학 조성, corticosteron에 미치는 효과를 조사하였다. 24주령의 산란 종계 총 105수를 3개 처리(대조구, GABA, probiotics), 처리당 7반복, 반복당 5수로 설정하여 사양실험을 실시하였다. GABA와 생균제는 배합사료 내 각각 50ppm과 0.1%로 첨가하여, 총 6주간 실험을 실시하였다. 전기간 산란종계의 평균 계란 생산량, 산란량은 대조구보다 생균제 급여 처리구에서 유의적으로 높았으며(P<0.05), FCR은 생균제 급여 처리구에서 낮은 값을 나타내었다(P<0.05). 산란 종계 계란의 난중, 난백고 높이, Haugh units, 난황색, 난각두께, 난각강도에서 처리구간의 유의적인 차이를 보이지 않았다. 또한 모든 혈청 생화학 조성에서 유의적인 차이를 보이지 않았다. 혈청 내 corticosterone 농도는 GABA와 생균제 급여로 인하여 대조구보다 유의적으로 감소하였다(P<0.05). 따라서 GABA와 생균제 급여 시 고온기 산란 종계의 스트레스를 완화시킬 수 있는 것으로 사료되며, 특히 생균제 급여는 계란 생산성 및 산란량 성적을 개선할 수 있는 것으로 나타났다.

• 한국동물위생학회지
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• 제16권1호
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• pp.82-89
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• 1993

In order to detection of the intestinal parasites, fecal samples were taken from broiler (n=262), laying hen(n=244), parent stock(n=207) and native stock(n=287) in Chonbuk province. The prevalence and identification of intestinal parasites were determined by the fecal examination using the floatation and /or sedimentation methods and microscopical examination, respectively. The results were obtained as follows : 1. The detection rate of parasite-eggs from 4 flocks(total=1,000) was 65.7%. 2. In the breed and type of breeding, infection rate of parasite-eggs was detected 84.0％ as native stock (floor breeding, 241 chicken), 79.7％ as parent stock (floor breeding, 165 chickens), 73.3% as broiler(floor breeding, 192 chicken) and 24.2% as laying hen(cage breeding, 59 chicken), in order. 3. In the concern of mixed infection such as single, double and triple, the rate was 55.1%, 8.7% and 1.9%, respectively. 4. Ten kinds of infective eggs were isolated from 657 fecal sample of 4 flock. They were classified 51.l% as Eimeria spp., 12.7% as Ascaridia galli, 5.1% as Capillaria spp., 4.1% as Strongyloides avium, 2.3% as Heterakis gallinarum, 0.5% as Hymenolepis spp., 0.3% as Railleina spp. and 0.2% as Syngamus spp., Trichostrongilus spp., or Choanoteania spp., single or in combination.

• 한국가금학회지
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• 제23권2호
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• pp.77-84
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• 1996

The purpose of this paper is to introduce the present situation of broiler breeder industry, and to investigate some problems related to it in Korea. The number of broiler breeding farms were 231 in 1990. It peaked to 264 in 1992, but decreased afterward to 232 in 1995. The number of broiler parent stock were over 4 millions since 1992 except in 1993. The number of commercial chicks produced per breeding hen was around 100, which is far below to the suggested values of breeding companies. The number of hatching eggs produced per breeding hen were 168 eggs in US, 156~170 eggs in Thailand, and 160~170 eggs in China. Factors involved in the lowered performances of broiler parent stock in Korea appear to be 1) the poor isolation of breeding farms from commercial broiler farms, causing easy contamination with various diseases, 2) the failure to provide proper environment to the breeder, and 3) the failure to control body weight during laying periods.

• 농업과학연구
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• 제49권1호
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• pp.61-75
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• 2022

The first purpose of this study is to evaluate the usefulness of pork traceability data, which is monthly time-series data, and to draw implications with regard to its usefulness. The second purpose is to construct a dynamic ecological equation model (DEEM) that reflects the biological characteristics at each growth stage, such as pregnancy, birth and growth, and the slaughter of pigs, using traceability data. With the monthly pig model devised in this study, it is expected that the number of slaughtered animals (supply) that can be shipped in the future is predictable and that policy simulations are possible. However, this study was limited to traceability data and focused only on building a supply-side model. As a result of verifying the traceability data, it was found that approximately 6% of farms produce by mixing great grand parent (GGP), grand parent (GP), parent stock (PS), and artificial insemination (AI), meaning that it is necessary to separate them by business type. However, the analysis also showed that the coefficient values estimated by constructing an equation for each growth stage were consistent with the pig growth outcomes. Also, the model predictive power test was excellent. For this reason, it is judged that the model design and traceability data constructed with the cohort and the dynamic ecological equation model system considering biological growth and shipment times are excellent. Finally, the model constructed in this study is expected to be used as basic data to inform producers in their decision-making activities and to help with governmental policy directions with regard to supply and demand. Research on the demand side is left for future researchers.

• 대한수의학회지
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• 제46권4호
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• pp.347-353
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• 2006

Serum samples of 30 chickens per flock from 6 grand parent stock (GPS) farms and 70 parent stock (PS) farms were collected for seroprevalent study of pullorum disease-fowl typhoid (PD-FT) infection by serum plate agglutination test (SPA). The incidence of PD-FT infection in GPS flocks and PS flocks were 0% and 15.7%, respectively. Especially PS flocks infected with PD-FT showed age dependent patterns that 22.2% of flocks between 20 to 30 weeks of age and 38.9% of flocks between 30 to 40 weeks of age were positive. The incidence of GPS flocks and PS flocks using Salmonella (S.) gallinarum 9R (SG9R) live vaccine were 33.3% and 58.6%, respectively. The sero-positive rate of 11 flocks were 6.7-83.3% by SPA and 2.9-55.6% by enzyme linked immunosorbent assay (ELISA), and ELISA showed more lower antibody levels than SPA. Furthermore, specific antibodies produced by SG9R vaccination were detectable by SPA using SG9R antigen without cross-reaction with the PD-FT infection.

• Journal of Korea Trade
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• 제23권5호
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• pp.1-26
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• 2019

Purpose - We examine the disclosures on foreign divestment from China by 77 Korean firms between 2007 and 2016 to identify the effects (and their determinants) on parent firm value. Design/methodology - We analyze how divestment affects firm value by examining the disclosure of divestment from China by Korean firms. Then, we examine the determinants of these disclosure effects using cross-sectional regression analyses. Findings - We find negative effects on parent firm value in the short and medium term, and both the KOSPI and KOSDAQ stock markets show negative correlations between foreign divestment and firm value. The parent firm's financial condition and profitability and the reason for divesting are statistically significant determinants. Practical implications - Most Korean firms in China belong to the manufacturing industry. As a result, divestment signifies a loss of important manufacturing bases and assets. Originality/value - We analyze foreign direct divestment, which has not been studied in detail previously owing to a lack of data. In addition, this research is the first to compare the disclosure effects in the KOSPI market with those in the KOSDAQ market for the same period.

• 한국동물위생학회지
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• 제29권1호
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• pp.65-70
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• 2006

In order to detection of the intestinal parasites, fecal samples were taken from broiler (n=290), parent stock (n=168) and laying hen (n=114) in Jeonbuk province. The prevalence and identification of intestinal parasites were determined by the fecal examination using the floatation method and microscopical examination, respectively. The detection rate of parasite-eggs from 3 flocks (total=572) was 44.9%. In the breed and type of breeding, infection rate of parasite-eggs was detected 65.5% as broiler (floor breeding, 290 chickens), 20.2% as parent stock (floor breeding, 168 chickens) and 28.9% as laying hen (cage breeding, 114 chickens), in order. In the concern of mixed infection such as single and double, the rate were 40.7% and 4.2%, respectively. Six kinds of infective eggs were isolated 257 fecal sample from 3 flock. They were classified 74.7% as Eimeria spp, 18.1% as Ascaridia galli and 6.0% as Capillaria spp and 0.4% as Heteratkis gallinarum, Railleina spp or Trichostrongylus spp, single or in combination.

• International Journal of Industrial Entomology and Biomaterials
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• 제3권2호
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• pp.187-190
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• 2001

Inheritance pattern of resistance to Bombyx mori nuclear polyhedrosis virus (BmNPV) was studied in an Indian silkworm stock TX by single back-cross test method. The resistant parent ［TX］, susceptible parent ［HM］, their Fl, F2, and Fl progeny back-crossed to TX [BC(R)] and HM [BC(S)] were inoculated per os with a fixed concentration of BmNPV($0.5{\times}10^{th} PIB/ml$) on the first day of second stadium. The cumulative mortality was recorded until day $10^{\times}$ post-inoculation. The results show that the resistance to BmNPV in TX fellow mono Mendelian inheritance pattern. The resistance dominated over the susceptibility at Fl. At F2, the resistant and susceptible offspring segregated in 3:1 ratio whereas at BC(S), the resistant and susceptible offspring segregated in 1:1 ratio. The response of BC(R) was more or less like the resistant parent TX which confirms the involvement of a major dominant gene conferring resistance to BmNPV in TX. The possible mechanism of inheritance of resistance in TX is discussed.