• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.1
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• pp.62-67
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• 1999

Infection rates of oyster ovarian parasite, Marteiliodes chungmuensis and productivity of the oyster shellstock infected with the parasite were investigated at the main seed collection areas in the southern coast of Korea where the extreme bad seed collection of oyster occurred in 1992 and 1993 to evaluate the cause of the bad seed collection. Additionally, the bacterial flora of the sea water and oyster lana were examined to identify the shellfish larva pathogenic bacteria like Vibrio sp. and Pseueomonas sp. In August 1992 to September 1993, infection rate of oyster ovarian parasite, M. chungmuensis at Tongyong, Kyongsangnam province, and Yosu, Chollanam province where the bad seed collection occurred, were $11.8\~100\%$ and $14.3\~100\%$, respectively. But the parasite was not detected in the shellstock collected at Daechon, Chungchongnam province. While a virus-like particle was identified in the cytoplasm of the egg infected by the parasite. The parasite infected egg was not able to fertilize completely. Uninfected egg in the gonad contaminated by the parasite could be able to fertilize but showed an abnormal development till D-shaped larva and then, died of necrosis after D-shaped lana. And some lana developed from low lipid content egg could not develop to the spat and died after the early umbo stage. The predominant bacteria in the oyster lana collected at bad seed collection areas were Pseudomonas sp. and Pseudomonas like bacteria and the occupancy rates were $53.3\~87.1\%$.

• Korean Journal of Poultry Science
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• v.44 no.2
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• pp.143-149
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• 2017

This study was carried out to collect basic data on the egg laying performance and disease occurrence on animal welfare-approved farms (AWAF) for laying hens with different housing types (windowless, open, and free-range house) and strains (Hy-line, Lohmann). Age at first egg laying was 151 d in the windowless house and 141 d in both the open and free-range houses, and the percentage peaks of each farm were 91.8%, 92.9%, and 86.3%. Average egg production according to housing types were 70.9%, 77.4%, and 65.6% at 18~38 wk old and 91.1%, 90.1%, and 76.2% at 32~36 wk. The average dirty and cracked egg ratio of the windowless, open, and free-range houses was 2.84%, 1.15%, and 0.23%, respectively. Mortality in the open house was lower than the other house types. Age of first egg laying for the Hy-line strain was 155 d and that for the Lohmann strain was 157 d, and the percentage peaks of the two strains were 92.9% (252 d) and 87.2% (237 d), respectively. Average egg production of the strains was 83.7% and 76.9%, respectively. The average dirty and cracked egg ratio of the Hy-Line and Lohmann strains was 3.85% and 2.97%, respectively. Mortality of the Hy-Line strain was lower than that of the Lohmann strain. There were significant differences (P<0.05) in the egg weight, HU, and egg yolk color of chickens raised in the open house compared with those of chickens raised in the other house types. In terms of antibody titer, that for Newcastle disease in open house chickens was lower than that of chickens raised in windowless and free-range houses. The antibody titer for low pathogenic avian influenza, avian infectious bronchitis, and avian pneumovirus was high at over 3.0 in all three farms. SG, Salmonella enteritidis, Salmonella pullorum, fowl adenovirus infection, and infectious laryngotrachitis were not detected in any of the three house types. The number of AWAF for laying hens has continuously increased in Korea, but there is currently little data on the housing types used on the AWAF for laying hens. Therefore, the results of the present study, in which analyzed the laying performance and disease occurrence on AWAF for laying hens, can use as basic data for the improvement of performance and prevention of disease on further AWFA for laying hens.

• Journal of Animal Environmental Science
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• v.13 no.1
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• pp.45-52
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• 2007

To evaluate the feed value of starfish, antimicrobial effects of its extract, nutrients contents, concentration of amino acids and its bioavailability were tested. Steaming and ether processes were applied to obtain the extract from starfish for antimicrobial effects examination. The starfish was dried at $60^{\circ}C$ for 3 days before grinding for processing and fermentation. Ground starfish(GS), extruded starfish(ES), fermented starfish(EFS) were added with enzyme and without enzyme(Non enzyme fermented starfish : NEFS). Then the nutrient composition and bioavailability of those were analyzed. The extract from starfish showed no inhibition of the growth of lactobacillus and pathogenic bacteria. Protein content showed significantly higher 62.86% and 52.82%, respectively in EFS and NEFS than GS and EGS(p<0.05). The Ca content of GS, EGS, EFS and NEFS was 17.26%, 18.26%, 5.37% and 8.55%, respectively. It was low in EFS and NEFS due to measure the Ca content after fermentation. Total amino acid was 17.17 mg/g, 20.28 mg/g, 36.30 mg/g and 29.96 mg/g in GS, EGS, EFS and NEFS, respectively. The ratio of total amino acid to protein tended to show the similar tendency as total amino acid. Both total amino acid and its ratio to protein were increased by the fermentation. Bioavailability of the protein and Ca showed more 80% in EFS and NEFS. The nutrients availability of EFS were significantly higher in laying hens than other treatments. The results of these experiments indicate that starfish would be applied as a feed ingredients if it was properly treated.

• Korean Journal of Veterinary Service
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• v.28 no.2
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• pp.121-146
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• 2005

Newcastle disease (ND), infectious bronchitis (IB), low pathogenic avian Influenza (LPAI) and fowl typhoid (FT) have been known as egg drop laying diseases because of the serious layer damage from mass zone layer. In this study, such egg drop laying diseases were investigated. To access this study, we peformed to evaluate antibody titers in serum and isolated bacteria and virus from organs and feces on May, July and September in 2003. The distribution of ND from January to May, IB and LPAI from October to February of the next year, and FT from March to September were inspected by the question survey in 21 farms. ND revealed to be positive rates of 490 to 474 $(96.7\%)$ in May, 510 to 506 $(99.2\%)$ in July and 510 to 510 $(100\%)$ in September with hemagglutination inhibition (HI) test. The mean antibody titers were 10.2, 9.9 and 10.2, respectively. With regard to IB, 484 out of 490 samples $(98.7\%)$ in May, 508 of 510 $(99.6\%)$ in July and 509 of 510 $(99.8\%)$ in September showed positive results and the mean antibody titers were gradually increased with 8.2, 9.0 and 9.4, respectively. According to HI test of LPAI, the positive results were shown in 442 of 480 $(92.1\%)$, 394 of 494 $(79.8\%)$ and 402 of 483 $(83.2\%)$ in May, July and September, respectively The mean antibody titers were decreased with 4.6, 4.3 and 4.0. The distribution of LPAI also elicited the positive rates of 480 to 475 $(99.0\%)$ in May, 494 to 485$(98.2\%)$ in July, 483 to 472 $(97.7\%)$ in September as determined by ELISA and the mean S/P ratio were 2.319, 2.557 and 2.380, respectively. Compared ELISA results with HI test of LPAI the positive results were 480 to 422 $(92.1\%),\;475(99.0\%),\;494\;to\;394 (79.8\%),\;485 (98.2\%)\;and\;483\;to\;402(83.2\%),\;472(97.7\%)$. Therefore, the positive rate determined by ELISA was higher than that of HI test with 6.9, 18.4 and $14.5\%$, respectively. When performed RT-PCR for ND using organ and feces samples, the pathotypes were detected $5(15.6\%)\;in\;May,\; 2(5.3\%) in\;July,\;2(7.1\%)$ in September but there is no samples showing positive band for LPAI. In attempt to isolate Salmonella gallinarum, bacteria were obtained from 4 cases (12.5%) in May, 9 (23.6%) in July, 5 (17.8%) in September. Thus the highest rate for isolation revealed to be shown in July When evaluated the antimicrobial susceptibility to 18 isolated strains of 5. gallinarum, bacteria were sensitive to trimethoprim/sulfamethox$(61.1\%),\;kanamycin\;(55.5\%),\;ampicillin\;(55.5\%)$ and amoxacillin/clavulanic acid $(55.5\%)$, cephalothin $(50.0\%)$, but resistant to penicillin $(88.9\%)$, streptomycin $(88.9\%)$, erythromycin $(83_4\%)$ and tetracycline $(61.1\%)$. According to HI test of ND and LPAI using captured 164 wild Korean tree sparrows (Passer nontanus), the positive rates were $47.6\%\;and\;57.3\%$, and the mean HI titers were 5.32 and 4.02, respectively. 71 $(43.2\%)\;and\;58(35.3\%)$ in captured sparrows also showed more than 4 titers for HI test to ND and LPAI, respectively However, the attempt for isolation of viruses failed in all samples.