• 한국유기농업학회지
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• 제29권4호
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• pp.507-521
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• 2021

The livestock farmers are producing under uncertainties such as Foot-and-Mouth Disease (FMD) and Free Trade Agreement (FTA). The purpose of this study is to strengthen the management capabilities of Hanwoo farmers to prepare them for the uncertainties just mentioned. To this end, this study was conducted to find the optimal rearing period in order to reduce the feed cost, which accounts for the largest portion of the operation cost of Hanwoo. Using the universal lattice model, 41,139 of 289,000 Hanwoo slaughter data from 2010 to 2019 were used for the FMD period and 246,605 heads for the general period. The results show that the maximum cutoff price of Hanwoo steer is 6,394,457 won at the 4th week of 27 months of age in general period, where as 6,242,752 won at the 2nd week of 26 months of age in the FMD period. Therefore, it is judged that it will be helpful for Hanwoo farms to maximize their business profits by slaughtering one month and two weeks earlier in the FMD period than in the general period. In addition, Hanwoo farmers need to break away from the conventional rearing method and improve their management efficiency through a more flexible rearing method.

• 한국수정란이식학회지
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• 제30권4호
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• pp.265-270
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• 2015

Growth rate during rearing, which varies depending on provided nutrition, has been related with age at $1^{st}$ calving (AFC). This study investigated the effect of upgrowth parameters during the rearing period on the reproduction of nulliparous Holstein heifers. The study comprised 77 successively born heifers from the same herd. Growth rate and fertility traits were measured during rearing and fertility parameters were recorded in lactations 1. Growth parameters (body weight, height, heart girth and body length) were measured at the approximate birth time, 270 and 450 d of age. Reproduction data collected included age at $1^{st}$ breeding, number of services per conception (S/C), pregnancy rate to $1^{st}$ artificial insemination, AFC. Animals were subsequently divided into 4 AFC groups for analysis: <23 mo, 23~25 mo, 26~30 mo and >30 mo. The AFC reflected both upgrowth rate and heifer reproduction, with later calving heifers smaller. Increased skeletal growth (at 270 and 450 d) was related with a reduced AFC (p<0.05). Early calving animals (<23 mo) had the best reproduction as nulliparous heifers, with most conceiving at first service (87.5%). Fertility in the first lactation was the worst in the oldest AFC group (>30 mo). In the 1st lactation period, a number of services per conception ($3.1{\pm}0.3$) increased with increasing AFC (>30 mo). Sub-optimal upgrowth related with an increased AFC could be mitigated by improved monitoring of replacement heifers during the rearing period.

• 한국응용곤충학회지
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• 제55권4호
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• pp.421-429
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• 2016

사료용 곤충 중에서 갈색거저리 유충은 사료용 및 산업용 등으로 이용되고 있지만, 효율적인 유충 확보를 위한 대량사육 연구는 미흡한 실정이다. 따라서, 본 연구에서는 갈색거저리 성충의 산란율 증가를 위한 밀기울+추가 사료 조건 별 산란율 비교, 산란 기간과 유충 크기의 균일성, 사육 밀도와 온도에 따른 발육 양상, 알과 번데기의 저온 보관 안정성을 검토하였다. 기본 사료인 밀기울에 당근과 애호박을 추가로 처리한 결과, 성충의 산란수와 생존율을 증가시킬 수 있었다. 성충의 산란 기간을 3일과 7일 동안 각각 달리한 결과, 14일 동안 산란을 받은 처리구에 비해 높은 유충 크기의 균일성을 확보할 수 있었다. 갈색거저리 유충의 발육은 20, 25, 30, $35^{\circ}C$ 조건 중에서 $30^{\circ}C$에서 가장 빨랐으며, $20^{\circ}C$에서는 산란수는 많았지만, 상대적으로 느린 생육 특성을 보였고, 자연 치사율이 증가하여 일정한 크기의 유충 확보가 용이하지 않았다. 사육용기에 갈색거저리 유충을 1, 10, 20, 30, 40, 50마리 밀도로 사육한 결과, 밀도가 증가함에 따라 유충의 생존율과 길이 생육에는 유의성 있는 영향을 주지 않았지만, 무게 생장은 감소하였다. 사육 밀도를 30마리(/직경 90 mm 용기) 이하로 유지하는 것이 가장 효율적이며, 30마리 이상으로 유지할 경우 개체의 발육이 늦어지는 결과를 확인하였다. 갈색거저리의 알과 번데기를 $4^{\circ}C$에 보관하였을 때, 알은 9시간, 번데기는 10주 이상 보관하면 부화율과 우화율이 급격히 감소하는 결과를 보여, 보관 충태는 알보다는 번데기가 더 적합하였다. 본 연구를 바탕으로, 갈색거저리 성충의 생존율과 산란율을 높이기 위한 추가 식물체 사료의 공급이 필요하며, 고품질의 균일한 충체 확보를 위해 산란을 7일 이상 받지 않을 것을 추천하고, $30^{\circ}C$ 근처의 사육온도에서 30마리/90 mm 용기 이하의 사육 밀도를 유지할 필요가 있으며, 저장 보관 과정에서 알보다는 번데기 형태로 보관하는 것이 적합하다. 본 연구의 결과는 효율적인 갈색거저리 유충의 대량 확보를 위한 기초자료로 활용될 수 있을 것으로 사료된다.

• International Journal of Industrial Entomology and Biomaterials
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• 제32권1호
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• pp.41-48
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• 2016

Mealworms, Tenebrio molitor (Coleoptera: Tenebrionidae), are widely used as food sourcefor animal rearing as well as human diet. Conventionally, mealworms raised on wheat bran. In this study, we investigated the effects of brewer's spent grain (BSG) on the growth of mealworm larvae to reduce the rearing cost. We prepared five different diets with various BSG content, 0, 10, 30, 50, and 70% of heated air dried BSG with wheat bran. We compared survivorship, larval weight, developmental duration, pupation rate, and pupal weight of five different groups of T. molitor raised on these five diets. The larval survivorships were almost similar with the control group except a group with 70% of BSG. For the larval weight, groups with 30% and 50% of BSG gained more weight than that with control treatment, 0% of BSG. For the developmental period, the groups with 30% of BSG took less time compared to the control group. In all treatment groups, more than 90% of pupation rate were observed. Especially, the group with 30% of BSG showed highest pupation rate among the five groups. Wheat bran with 30~50% of BSG was the optimal diet for successive insect rearing among the five diet treatments. Based on this study, we concluded that adding BSG to wheat bran helps to improve the quality of T. molitor and to reduce the rearing period.

• 한국해양공학회지
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• 제13권4호통권35호
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• pp.143-150
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• 1999

Multipurpose fisheries base was conceptually designed to establish marine ranching system in the coastal waters around Tongyoung, southern sea of Korea. Fisheries base for marine ranching system has integrated various facilities which were required for the process of spawning, rearing, training, releasing, monitoring and catching functions. This base has five steel piles for supporting upper structure and systems. Four steel piles are surrounded by circular net pen made by steel wire, they have the function of the protection against fouling for pile and scouring for bottom soil as well as secondary rearing and short stocking. We can use the last pile to moor a ship and access to the base. Principal structure with steel piles is designed by optimization technique considering design external forces in the coastal waters of return period of 50 years. Design optimization Problem is formulated for this base. Optimal design of multipurpose fisheries base is numerically investigated by sequential quadratic programming method.

• 한국잠사곤충학회지
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• 제53권1호
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• pp.1-5
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• 2015

갈색거저리의 산업 활용도가 높아짐에 따라, 효율적인 실내 대량사육 시스템의 확립이 더욱 중요하게 인식되고 있다. 본 연구는 대량사육을 위해 다양한 범위의 온도, 광주기, 사육밀도에서 갈색거저리의 생리적 특성을 알아보고자 수행되었다. 갈색거저리 알은 $17.5{\sim}27.5^{\circ}C$에서 70% 이상의 부화율을 나타냈고, 부화기간은 $25{\sim}35^{\circ}C$에서 5~7 일로 조사되었다. 결과적으로, 부화율과 산란 전 기간(egg periods)을 고려했을 때, 대량사육을 위해 적절한 실내온도는 $25{\sim}27.5^{\circ}C$였다. 다양한 온도 조건하에서 대량사육 시스템에서 유충의 발육기간은 개별사육 시스템에서 보다 더 짧았다. 번데기 무게는 $20^{\circ}C$와 $25^{\circ}C$를 제외한 대량사육 시스템에서 좀 더 높게 관찰되었다. 수요 탄력성과 생산중량을 고려했을 때, 가장 효과적인 조건은 $25^{\circ}C$에서 대량사육한 실험군이었다. 14L : 10D의 광주기 조건에서 157.35일로 가장 짧은 유충기간을 나타냈다.

• Journal of Biosystems Engineering
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• 제31권5호
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• pp.436-442
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• 2006

This research was conducted to design and develop a wired monitoring system for judging if sick or dead layers (SDL) exist in multi-tier layers battery (MLB) by machine vision, and to analyze its performance. In this study, 20 Brown Leghorn (Hi-Brown) layers aged 37 weeks old, were used as the experimental animals. The intensity of concern paid by layers on feed was over 90% during 5 minutes and 30 seconds after providing feed, and normal layers (NL) had been standing to take feed for that period. Therefore, in this study, the optimal judging time was set by this test result. The wired monitoring system developed was consisted of a driving device for carrying machine vision systems, a control program, a RS232 to RS485 convertor, an automatic positioning system, and an image capture system. An image processing algorithm was developed to find SDL in MLB by the processes of binary processing, erosion, expansion, labeling, and reckoning central coordinate of the captured images. The optimal velocity for driving unit was set up as 0.13 m/s by the test results for wired monitoring system, and the proximity switch was controlled not to be operated for 1.0 second after first image captured. The wired monitoring system developed was tested to evaluate the remote monitoring performance at lab-scale laying hen house. Results showed that its judgement success.ate on normal cage (without SDL) was 87% and that on abnormal cage (with SDL) was 90%, respectively. Therefore, it would be concluded that the wired monitoring system developed in this study was well suited to the purpose of this study.

• 한국패류학회지
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• 제30권3호
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• pp.219-226
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• 2014

본 연구는 해상가두리에서 2년 동안 수용밀도별로 사육된 북방전복 (Haliotis dicus hannai) 의 성장 및 생존율 조사를 통해 적정 수용밀도를 구명하고 생산성을 향상시키고자 수행 하였다. 수용밀도는 쉘터 단면적 당 점유율로 15, 30, 45, 60 percentage $(=per.)/m^2$로 설정하여 약 1년을 기준으로 1차 양성기간 (the primary rearing period, PRP), 2차 양성시간 (the second rearing period, SRP) 으로 실시하였다. PRP와 SRP의 1년간 평균 수온은 $2^{\circ}$의 차이를 보였다. PRP의 북방전복 (평균각장 $36.14{\pm}2.28mm$) 은 성장에서 각장과 각폭의 절대성장율 (absolute growth rate, ARG), 일간성장율 (daily growth rate, DGR), 특수생장율 (specific growth rate, SGR) 에서 $15per./m^2$ 유의적으로 높았고 (P < 0.05), 생존율은 차이가 없었다. SRP의 북방전복 (평균각장 $55.26{\pm}6.93mm$) 은 ARG, DGR, SGR에서 $45per./m^2$제외한 실험구간 유의적 차이는 없었으며, 생존율은 저밀도인 15, $30per./m^2$는 70% 이상을 보였으나, 고밀도인 45, $60per./m^2$는 각각 31%, 9%이하였다. 본 실험결과 해상가두리 내에서 각장 3-4 cm 북방전복의 1차 양성기간 적정 수용밀도는 $15per./m^2$ ($2.4{\times}2.4m$, 1칸 당 750마리) 가 적정하였다. 2차 양성기간 육성용 북방전복 (각장 5-6 cm) 은 경제성을 고려하여 $30per./m^2$인 양성하는 것이 양식 생산성을 향상시킬 수 있을 것으로 판단된다.

• 한국응용곤충학회지
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• 제43권2호
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• pp.135-141
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• 2004

본 연구에서는 왕사슴벌레의 국내 분포지가 재검토되고 이들의 대량사육기술 개발을 위한 생태적 특성이 조사되었다. 산란수를 최대화하기 위해서는 우화 후6개월이 지난 암, 수 성충에게 2주 이상의 교미기간이 허용되어야 하며 성비는 암：수 = 2：1이 이상적이었다. 산란수는 암컷 한 마리 당 최대 27.3개이고 알은 한 개씩 산란된다. 산란전기간은 평균 147.3일, 산란기간은 최소 120일 이었으며 난기간은 평균 15.6일이었다. 산란상은 직경 15cm${\times}$길이 15cm인 산란목이 3-4개 들어 있는 55${\times}$40${\times}$35cm크기의 산란상이 이상적이었다. 산란목으로는 상수리나무가 선호되었다. 사육실조건($25^{\circ}C$, 75% R.H., 16L：8D)에서 1령기간은 24.1일,2령은 29.8일, 3령에는 131.2일이 소요되었으며 용기간은 28.9일이 소요되었다. 성충수명은 35개월 이상이었다. 산란수를 증가시키기 위해서는 최소 3-4개월의 휴면기간이 필요한 것으로 밝혀졌다.

• International Journal of Industrial Entomology and Biomaterials
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• 제28권2호
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• pp.51-57
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• 2014

Bumblebees are important pollinators of crops and wildflowers. The Korean native bumblebee, Bombus ignitus, undergoes one generation per year, and induction of artificial hibernation is essential for year-round rearing of the bumblebee. Keeping queens under cold treatment conditions for several mo is an effective method for terminating their diapause and promoting colony development. In the present study, we investigated how the timing and duration of chilling affect the artificial hibernation of B. ignitus queens. In the timing assessment, cold treatment was instituted at 12 d, 40 d, or 100 d after eclosion under a constant temperature of $5^{\circ}C$ and 80% humidity. The queens that entered cold treatment at 12 d after emergence evidenced the highest survival rates: 86.7% at two mo, 73.3% at three mo, and 46.4% at 4 mo. Survival rates were reduced under storage conditions at 12 d, 40 d, and 100 d after emergence. When queens were subjected to chilling at 8 d, 12 d, or 16 d after eclosion with constant 80% humidity, the queens stored at 12 d after eclosion exhibited the highest survival rates, which were 84.6 at one mo, 25.0% at two mo, and 7.9% at three mo. In regards to the duration of the cold period, the queens that hibernated for at least two mo evidenced optimal colony development rates. The rates of oviposition, colony foundation, and progeny-queen production of queens hibernated for two mo were 60.0%, 30.0%, and 13.3%, respectively. These values were 6.0 to 13.3 times higher than those in the queens that hibernated for 15 d. Therefore, a cold period of at least 2 mo applied 12 d after emergence were found to be the most favorable conditions for diapause break in B. ignitus queens.