• Korean Journal of Ichthyology
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• v.32 no.3
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• pp.166-181
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• 2020

The egg development, early life history and spawning site characters of Korean endemic fish, Coreoleuciscus splendidus (Gobioninae), were investigated at the part of Jo-jong stream in Korea from May 2020. The fertilized eggs were 2.05~2.23 mm (mean, 2.13 mm) in diameter and had no oil globules. The embryo began to hatching about 98 hrs after fertilization under water temperature of 20±1℃. The newly-hatched larvae were 5.03~5.68 mm (mean, 5.31 mm) in total length (TL), and their mouth and anus were not opened. 4 days after hatching, Several rod-like cupulae were observed on the head and lateral side of the body at 6.95~7.89 mm (mean, 7.51 mm). 7 days after hatching, the post-larva stage were 8.39~9.29 mm (mean, 8.78 mm) in total length, and their york were completely absorbed. The cupulae were completely distinguished. They entered the juvenile stage when all fin-rays were formed at 29 days after hatching, and their TL were 14.16~17.04 mm (mean, 14.99 mm). Squamation was initiated on the caudal body at approximately 18.21~23.74 mm (mean, 30.28 mm), 38 days after hatching, and completed at 26.82~33.33 mm (mean, 19.42 mm), 73 days after hatching, the external characteristics from of juveniles were same to adults. The spawning site was characterized by bottom structure of pebble (64~16 mm) and gravel (16~2 mm), environmental conditions of the spawning sites were 6~18 cm in water depth, 0.43~0.73 m/sec in bottom water velocity. In spawning sites, an egg mass or separated eggs were located a small gap of under the pebble and gravel.

• Korean Journal of Ichthyology
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• v.31 no.1
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• pp.7-15
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• 2019

The present study aimed to investigate the influence of starvation on growth, survival and swimming ability of Pacific cod Gadus macrocephalus larvae. Notochord length, musculature height, body depth, gut height and volume of yolk of reared larvae were measured to determine the growth parameters. A significant difference was observed in all morphometric characteristics before 15 DAH (days after hatching). Body depth and volume of yolk of unfed larvae were significantly smaller than those of fed larvae from 9 DAH (P<0.05). Almost all yolk in fed group was consumed at 11 DAH. Survival and growth of larvae were observed to determine the effect of delayed initial feeding (2 DAH, 3 DAH, 4 DAH, unfed). All larvae in the unfed group died by 15 DAH and the larvae in other experimental groups survived until the end of the experiment to 21 DAH. Survival rate was not significantly different between the 2 DAH group ($17.5{\pm}4.27%$) and the 3 DAH group ($20.5{\pm}1.5%$) at 21 DAH (P>0.05). However, there was a significant difference in survival rate between the 3 DAH group and the 4 DAH group ($11.7{\pm}1.52%$) (P<0.05). There was no significant difference in notochord length among the groups fed from 2 DAH, 3 DAH and 4 DAH at 21 DAH (P>0.05). The swimming ability in fed group gradually increased in both cruising and burst swimming speeds, while those abilities in unfed group gradually decreased after reaching the peak at 6 DAH in both cruise ($18.7{\pm}6.56mm/s$) and burst swimming speed ($43.5{\pm}12.65mm/s$).

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.2
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• pp.144-149
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• 2018

The eggs are incubated for 18 days through the generator and incubated in the developing incubator. During the developmental period, the weight loss of the fetus is correlated with the ventricular formation, and the proper ventricular formation is also associated with the healthy embryonic hatching and the egg hatching rate. However, in the incubator period of the domestic hatchery, it is a reality to acquire the resultant side by the Iranian standard weight measurement with the experience of the hatchery and the person concerned and the development period without the apparatus for measuring the present weight. As a result, prevalence of early mortality, hunger and illness during hatching are frequent. Monitoring the reduction of weaning weight is crucial to obtaining chick quality and hatching performance with weight changes within the development machine. Water loss is different depending on the size of eggs, egg shell, and elder group. We can expect to increase the hatching rate by measuring the weight change in real time and optimizing the ventilation change accordingly. There is a need to develop a real-time measurement system that can control 10 to 13% reduction of the total weight during hatching. The system through this study is a way to check the one - time directly when moving the existing egg, and it is impossible to control the measurement of the fetal water evaporation within the development period. Unlike systems that do not affect the hatching rate, four load cells are connected in parallel on the Arduino sketch board and the AT-command command is used to connect the mobile phone and computer in real time. The communication speed of Bluetooth was set to 15200 to match the communication speed of Arduino and Hyper-terminal program. The real - time monitoring system was designed to visually check the change of the weight of the fetus in the artificial incubator. In this way, we aimed to improve the hatching rate and health condition of the hatching eggs.

• Korean Journal of Environmental Biology
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• v.23 no.1
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• pp.27-31
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• 2005

Early larval growth for total length (TL) and body weight (BW) in flesh prawn (Fenneropenaeus chinensis) was studied from hatching to 25 days after hatching. Mean total length at nauplius and zoea stages was 0.21-0.39 mm and 0.62-1.03 mm, respectively. Mean total length of mysis stage grew from 1.28 mm (9 days after hatching) to 5.98 mm (21 days after hatching). The increase of body weight during experimental period showed step by step growth pattern due to metamorphosis of this species. The relationship between BW and TL from hatching to 25 days after hatching was BW = 2E-5TL/sup 4.1707/ (r²= 0.9746).

• KOREAN POULTRY JOURNAL
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• v.4 no.8 s.34
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• pp.57-60
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• 1972

여기 산란계 10,000수를 확보한 양계장 주인이 있다고 가정하자. 대부분 다른 사람과 마찬가지로 그도 사소한 일에 도저히 신경쓸 겨를이 없었으나 몇달전 주의를 환기, 첵크해보니 계란 1타스 생산에 약2kg의 사료가 소비됨을 알았다. 그는 사료소비가 약간 높다는 것을 알았지만 사료를 허비하여 비용이 올라가는 줄은 몰랐다. 어느날 부화장 세일즈맨이 와서 계란 1타스 생산에 필요한 기준 사료 요구량은 약 1.86kg라고 했다. 그때 그는 계란 1타스당 140g의 사료가 낭비됨을 알았다. 그래서 곰곰히 계산해보니 1년에 1마리가 계란 20타스 생산하면 1타스당 140g 손실이니 20타스면 2.8kg의 사료를 낭비하고 년간수당 140원의 돈을 버리고 있음을 알았다. 1마리당 140원의 손실은 10,000수면 140,000원의 돈을 매년 버리고 있음을 발견하고 깜짝 놀라지 않을 수 없었다. 다행이도 그는 사소한 사료의 손실이 수익에 얼마나 손해를 끼치게 되는가 알게된 것이다. 그때부터 그는 고용인에게 하루 1회 사료를 주던것을 2회로 나누어 주도록 하고 사료운반통은 좀더 서서히 끌도록 하였다. 지금 그는 계란 1타스당 1.86kg의 사료를 소비하고 있으며 사소한 손실에 신경을 쓴 댓가로 전보다 1년에 140,000원의 돈을 더 벌고 있다.

• Monthly Duck's Village
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• s.64
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• pp.64-67
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• 2008

국내에 종오리(PS)를 수출하고 있는 프랑스 오리 육종전문회사 "그리므드(Gremaud Freres)"에서 현재 오리 품종이 개량 및 사양관리를 담당하고 있는 로렌트 버나드(Laurent Bernard)박사가 지난 9월 1일 한국을 방문하였다. 이번 내한 목적은 현재 그리므드사의 종오리를 수입하고 있는 국내 부화장 및 계열 업체를 방문하여 현재 사육 중인 STAR-53 종에 대한 의문점을 풀어주고 개선사항 등 전반적인 사양관리에 대한 노하우를 전수하기 위한 것이다. 로렌트 박사는 지난 2월 방문때와 마찬가지로 사육시 주령별 체중이나 사료급이나 등을 철저히 기록하고 분석하여 정확한 데이터를 보유하고 있어야만이 그리므드사에서도 보다 한국실정에 맞는 오리의 육종이 가능할 수 있다고 재차 강조하였으며 앞으로 STAR 종의 육성율 및 산란율을 증대시키기 위해 최선을 다 할 것을 다짐하였다.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2006.11a
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• pp.86-87
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• 2006

The hatchery sanitation has a significant impact on chick quality. This study was carried out to investigate the bacterial contamination in the broiler hatchery. The aerosol bacterial contamination was low except for the operating hatcher that the bacterial counts were measured almost over 300 counts/64cm$^{2}$. The bacterial contamination of the facilities and equipments had a similar tendency as compared with the aerosol bacterial contamination. More than six groups of the Salmonella species were isolated almost from the hatcher and the related facilities and equipments. Also, in this study, we compared the effects of four methods of 37% formalin adminstration in hatcher. At hatch, the aerosol bacterial counts in hatcher receiving 37% formalin as constant rate infusion method during hatching were significantly lower than in each hatcher receiving 37% formalin once at transfer and not receiving 37% formalin, respectively(p<0.05).

• Monthly Korean Chicken
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• s.130
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• pp.76-80
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• 2006

해마다 2~3월은 복 물량 대비 병아리 발생이 시작되는 시기로써 이른바 초산병아리가 부화장마다 분양되고 있다. 올해도 역시 초산병아리가 현장에 많이 분양되면서 2~3월에 생산성이 극히 낮아지는 현상이 반복되었다. 물론 극히 일부 초산을 제외하고 초산이든 노계든 그에 맞는 사양관리를 정상적으로 해 준다면 큰 문제가 없으나 생산성이 낮은 농장에서는 초산병아리가 입실되어도 피크병아리가 입식됐을 때와 마찬가지로 사양관리를 해 주기 때문에 문제가 발생하고 있다는 것이 필자의 판단이다. 육추관리는 모든 것을 잘해줘야 하지만 특히 초산병아리가 입식 됐을 때는 피크 병아리가 입식됐을 때보다 두 배의 관리를 해줘야 정상관리를 할 수 있다. 그런 관리를 하지 못했을 때 가장 문제가 되는 것이 층아리가 발생하여 계군 균일도를 떨어뜨리는 문제이다. 2~3월달 농장을 방문하면서 이점이 가장안타까웠기에 필자가 다시 한번 펜을 들게 되었다. 육계는 마라톤이 아니라 단거리인 100m달리기와 같아서 입추기간동안은 육추관리는 100m에서의 '스타트'와 같아서 그 기간이 바로 사육성적을 결정하고 후에 회복할 시간이 없다. 문제된 병아리가 입식되어도 정상적인 육추관리를 해 준다면 피해를 최소화 할 수 있음을 강조하고 싶다.

• KOREAN POULTRY JOURNAL
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• v.36 no.7 s.417
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• pp.112-115
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• 2004

최근 국내 양계산업을 둘러싸고 있는 여러 여건들을 볼 때 가슴조이는 긴장의 연속이라고 말할 수 있다. 작년 12월 전 세계를 놀라게 한 조류독감(AI)은 우리 닭고기 시장을 얼어붙게 하였으며, 또한 국제 옥수수 수송비 상승과 함께 국내 사료 가격은 불과 6개월 사이에 3차례에 걸쳐 $30\%$ 가까이 올랐고 국제유가도 가파른 상승세를 지속하고 있다. 이러한 고유가, 고사료가 시대를 맞은 우리 양계산업의 경쟁력은 상대적으로 약화됨과 동시에 닭고기 수입량의 증가와 계란 소비의 둔화, 그리고 불안정한 가격체계 등 여러 어려운 문제점들이 현안으로 떠오르고 있다. 이와같이 국제화 시대에 가격 경쟁력을 약화시키는 주요인으로는 병아리 품질 저하와 낙후된 계사시설을 들 수 있으며, 이중 병아리의 품질저하는 우리나라 종계장과 부화장이 영세한데다 병아리의 수급 물량이 쉽게 급변하는데 기인하고 있으며 계사 시설의 낙후는 아직도 생산농가의 사육규모가 영세한데 따른 것으로 볼 수 있다.

• Korean Journal of Ichthyology
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• v.17 no.2
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• pp.105-111
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• 2005

Most of the eggs and (or) pre-larvae of Acheilognathus signifer were observed from the gills of Unio douglasiae sinuolatus, 30~45 mm in the shell length, that is the host mussel of A. signifer. There was no selectivity in proportion to mussel size at the range observed. One to seven individual eggs and (or) pre-larvae were found in the mussels, with a mean of 2.5 individuals, and the rate of possessing one egg and (or) pre-larva was 50.0%. When the prelarva of A. signifer acquired swimming ability inside the mussel, it moved into the suprabranchial chamber. It was estimated that the growth period was 4~6 weeks. The minute tubercles of the pre-larvae were observed immediately after hatching. Absorption of the minute tubercles was observed starting the 7 th day, with most of tubercles absorbed 13 days after hatching and completed 20 days after the yolk was entirely absorbed.