• International Journal of Industrial Entomology and Biomaterials
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• 제19권2호
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• pp.243-248
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• 2009

The Larval critical weight is the minimal mass at which further growth in not necessary for a normal time course to pupation. Larval critical weight (Lcw), pupal critical weight (Pcw) and adult critical weight (Acw) of different breeds of Bombyx mori L. were determined through starvation (food deprivation). The Lcw was found to be about 938.46, 2397.26, 2283.57 and 2220.97 mg in males and 1118.15, 2681.04, 2604.9 and 2455.88 mg in females of the multivoltine breed (Nistari), Bivoltine breeds (P5 & NB18) and their hybrid (P5$\times$NB18) respectively. Bivoltine breed P5 took more time (3.35 days) followed by NB18 (3.13 days) & P5$\times$NB18 (3.02 days) to attain larval critical weight (In $5^{th}$ Instar) than the multivoltine breed Nistari (2.42 days). Decrease in weight from larval maximal weight to pupal weight and to adult weight was also observed more in multivoltine than bivoltines, which may be due to more latent feeding period in bivoltines. Since Lcw is a stable character and independent of environment, it could be utilized for characterization of silkworm breeds to assess the quality of an insect.

• International Journal of Industrial Entomology and Biomaterials
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• 제32권2호
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• pp.69-79
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• 2016

Distillers dried grain (DDG) and makgeolli spent grain (MSG) are agricultural byproducts to produce alcoholic beverage. However, they are known to contain enough nutrients. Mealworm is a promising insect resource for an animal feed ingredient as well as alternative human food. With low cost, DDG and MSG were investigated as a feed ingredient for rearing high quality mealworms. DDG and MSG were mixed with wheat bran and compared to control feed (only wheat bran) for its effects on larval survivorship, larval weight, duration for developmental period, pupation rate, and pupal weight. When DDG added, larval survivorship was reduced to 50~70% compared to the control group. Larvae fed on DDG were heavier from third to sixth week. Especially, larvae with 50% DDG were 28% heavier than the control group at the third week. For the larval period, the 50% DDG group was 11% less than that for the control. The pupal weight for the 30% DDG group was 7% heavier than that for the control group. Pupation rates for all the DDG groups were higher than 90%. When compared to the control, larval survivorship for the 70% MSG group was low, but the 50% and 70% MSG groups were high during the seventh and eighth weeks because of delayed development. After the eighth week, larvae with 70% MSG showed the highest larval weight increase as 9~18% compared to the control group. Except 70% MSG group, all of MSG groups showed more than 90% pupation rates. We confirmed that adding 30~50% of DDG or MSG to conventional wheat bran have a strong potential to replace the conventional wheat bran insect feed for quality insect production.

• 한국수산과학회지
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• 제53권6호
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• pp.894-899
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• 2020

This study investigated the effects of inclusion of pollock oil (PO) in the diet of broodstock on the egg and larval quality of Walleye Pollock Gadus chalcogrammus. The experimental diet comprised of semi-moist pellets prepared either with or without PO (control; Con). The fish assigned to each diet were fed to visual satiation (two meals per day) for 12 weeks. Eggs spawned from both groups of fish were sampled during the spawning season (three months) and the egg and larval quality was determined. Total egg volume, fertilization, and hatchability of eggs from the PO group were higher than those of the Con group. Fatty acid composition of fertilized eggs was not affected by the experimental diet. Oleic acid, eicosapentaenoic acid, and docosahexaenoic acid content in larvae of the PO group was higher than that in larvae of the Con group. These results demonstrate the beneficial effects of including PO in the broodstock diet of Walleye Pollock, specifically on the quality of the eggs (total egg volume, fertilization, and hatchability) and larvae (fatty acid composition).

• 한국어병학회지
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• 제23권3호
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• pp.303-311
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• 2010

이전의 연구에서 참가리비(Patinopecten yessoensis) 인공종묘생산 중 수질관리를 위해 주기적으로 실시하는 환수(전량환수)가 scuticociliates 감염을 촉진 할수 있다는 가능성을 제기하였다. 본 연구에서는 수질과 scuticociliates 감염을 고려한 최적 환수 횟수를 결정하고자 하였으며, 유생성장, 생존, scuticociliates 발생을 1차 기준으로 하였으며, 부가하여 중간 육성장으로 이동하여 성장 및 기형 발생율을 2차기준으로 조사하였다. 5일 간격의 환수(3T)가 가장 좋은 결과를 보였다. 잦은 환수(5T)는 수질 개선에도 불구하고 성장 둔화가 확인되었으며, 이것은 scuticociliates의 감염과 연관이 있는 것으로 보였다. 9일간격의 환수(1T) 역시 성장둔화를 보였으며, 5T 실험구와 더불어 중간육성이후 성장 둔화(통계적 유의성 없음)와 비정상 발생을 유발하였다. 본 연구결과 최적 환수간격은 5-7일 사이로 나타났다.

• 한국수산과학회지
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• 제54권6호
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• pp.948-953
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• 2021

To find the optimal eggs to larvae transforming temperature of walleye pollock Theragra chalcogramma, we investigated their hatching pattern, mortality, and larval deformities. Results showed that the hatching quality decreased as the water temperature increased and dropped sharply above 13℃. The highest hatching rate was achieved at 7℃, whereas the lowest was at 15℃. Dead eggs were not observed at 7℃; however, dead egg ratios were significantly high at 4.5℃ and above 13℃ (P<0.05). Mortality of larvae after hatching was not observed at 4.5℃, but was significantly high above 13℃. The DNA content of the larvae did not show any significant difference at all water temperatures; however, RNA content was the highest at 7℃ and was significantly low above 11℃. In addition, RNA/DNA ratio was the highest at 7℃. Larval deformities after hatching were low at 7-11℃ and higher at higher or lower water temperature. Therefore, the hatching index and larval health index of Walleye pollock eggs in this study show that 7℃ to 11℃ seems to be the optimal transforming water temperature range.

• 한국수산과학회지
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• 제44권5호
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• pp.516-523
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• 2011

To compare four populations of sea squirt Halocynthia roretzi adults, their egg quality and larval development were investigated in the hatchery. The populations were: south sea wild (SSW), south sea cultured (SSC), east sea wild (ESW) and Iwate Japan cultured (IJC). Egg quality and larval development were compared using 13 factors (fertilization rate and diameter, proximate composition, amino acid and fatty acid contents of eggs, hatching rate and various sizes of tadpole larvae) which were obtained from each population. Fertilized egg diameter, hatching rate and size of tadpole larvae were significantly different among the four populations (P<0.05). Eggs were produced with higher crude protein ($5.20{\pm}0.00%$ SSW, $4.71{\pm}0.01%$ ESW, $4.66{\pm}0.01%$ SSC and $3.96{\pm}0.01%$ IJC) and lipid ($1.22{\pm}0.01%$ ESW, $1.01{\pm}0.00%$ SSW, $0.77{\pm}0.01%$ SSC and $0.69{\pm}0.00%$ IJC,) contents from domestic wild populations than from Japanese or cultured populations. Also amino acid and fatty acid contents were different. The extent of similarity between domestic and Japanese populations (30.5% IJC:SSW, 34.3% IJC:SSC and 40.7% IJC:ESW) was relatively low but was very high between SSW and SSC (73.9%). These results may have been due to differences in the abundance of food types and environmental conditions in the four localities and consequent differences in the diets of the sea squirts.

• 한국잠사곤충학회지
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• 제16권1호
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• pp.93-100
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• 1974

농약으로 오염된 뽕을 누에에게 급여했을 때 누에의 사육성적과 견질에 미치는 영향을 알아보기 위하여 살충제를 사용하여 실험한 결과 다음과 같은 몇가지 결과를 얻었다. 1. 1,000배액의 살충제를 뽕잎에 살포한 후 25일 자연 방치하였다가 급여하여도 감잠비율이 증가하였다. 2. 농약오염뽕의 누에첨식사육결과 사육성적에 미치는 영향은 살충제별로 차이가 있다. 3. Lebaycid의 첨식구에서는 탈항잠이 출현하였다. 4. 농약오염뽕의 누에첨식사육은 불정형견과 이상견사의 원인이 된다.

• 한국잠사곤충학회지
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• 제27권1호
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• pp.18-23
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• 1985

인공사료육 누에에 있어서 사료조성 차이와 사육환경이 누에의 성장발육에 미치는 영향은 다음과 같다. 1. 사료의 대두분말 함량이 많을수록 경과가 짧았으나 대두분말 함량이 50%를 넘으면 오히려 경과가 길어졌다. 2. 감잠비율은 대두분말 함량비가 50%까지는 영향을 미치지 못하지만 그 이상에서는 높았다. 3. 사료조성 차이가 견질에 미치는 영향은 단견중에 있어서는 단백질 함량이 많을수록 무겁고 견층중은 차이가 없었으며 견층비율은 대조구에 비해 각 처리구 모두 낮았다. 4. 사육환경 중 온도는 고온이 광선은 암조건이 경과를 단축시켰다. 5. 감잠비율은 치잠기 고온에서 낮았고 광선은 암조건에서 낮았다. 6. 사육환경이 견질에 미치는 영향은 단견중, 견층중, 견층비율 모두 온도는 고온이, 광선은 암조건이 양호하였다.

• 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.

• 한국수산과학회지
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• 제35권4호
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• pp.315-320
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• 2002

통영을 중심으로 한 우럭생산량은 연간 1,813M/T에 이르고 있으며, 과잉생산에 대한 우려가 제기되고 있다. 이와 같은 우려를 개선시키고 기능성 어류에 대한 소비자의 기대감을 충족시키기 위하언 성장촉진, 항암, 면역증강, 혈중 LDL 함량 저하효과를 가진 것으로 알려져 있는 CLA를 이용한 기능성 우럭생산의 가능성을 검토하였다. Artemia 영양강화시 CLA를 $0.5\~5.0\%$ 첨가하였을 경우 Artemia중 지방산조성의 변화를 조사한 결과 CLA 첨가량이 증가할수록 CLA 함량은 높아졌고, 동시에 Artemia 특유의 지방산조성을 나타내어 지방산 대사에 특별한 영향을 미치지지는 않는 것으로 나타났다. 8주 사육 후 우럭근육 중 n-6지방산의 함량이 높아 사료에 첨가된 지질의 영향을 받은 것으로 나타났다. 그리고 n-3/n-6 PUFA 비가 자연산 우럭의 3.95보다 현저히 낮아 CLA 첨가가 많을수록 성장을 저해하는 것으로 나타나 배합사료 중의 DHA 첨가가 증가되어야 할 것으로 여겨진다. 그러나 이를 섭취한 우럭 근육 중 총 CLA 함량은 급이 량에 따라 각각 $6.57\~16.07\%$가 축적되어 CLA는 다른 지질성분과 함께 어체내 대사과정을 거치는 것으로 나타났다. 우럭의 성장도, 사료효율, DHA/EPA 비, n-3/n-6 PUFA 비, 활력테스트, 혈액지수 둥을 비교하였을 때 $1.0\%$ CLA 첨가가 적절한 첨가량인 것으로 생각된다.