• International Journal of Industrial Entomology and Biomaterials
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• 제3권2호
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• pp.135-139
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• 2001

Experiments were held in Egypt to test a new Package of practices for commercial cocoon production, including adding secondary macro and micronutrients to the mulberry garden, disease free rearing regime, low temperature rearing in young instars and natural mounting fur silkworms. This package for seed silkworm rearing lead to increase in fecundity by 67-121eggs (15.12-26.22%) and yield of standard boxes per 1 parent egg boxes by 57-58 egg boxes(48.33-51.66%) respectively in comparison th the traditional cocoon production technology.

• 한국양식학회지
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• 제14권1호
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• pp.29-33
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• 2001

Total length and body weight of grey mullet were 6.4cm and 2.1g, respectively at the beginning of the experiment. After 60 days of rearing, body weight of the mullet(363%) was significantly higher in freshwater group than that (187%) in seawater group. However, the condition factor showed no significant differences between seawater (9.0%) and freshwater (8.8%) groups. Survival of the mullet was 98.3% and 64.3% in seawater and freshwater groups, respectively.

• 한국양식학회지
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• 제1권1호
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• pp.13-24
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• 1988

양식용 넙치 종묘의 효율적인 대량생산 방법에 관한 기초적 자료로서 치어의 사육밀도를 검토함과 동시에 고밀도사육의 가능성에 대하여 조사하고자, 폐진순환여과 사육수조를 전장2.53$\pm$0.24 cm, 체고 1.12$\pm$0.12 cm의 넙치치어를 저면적 137.75 $cm^2$당 10개체 (D10), 20개체 이용하여 (D2O), 30개체 (D30) 및 40개체 (D40) 식수용한 4개 밀도구를 설정한후 65일간 사육한 결과는 다음과 같다. 사육기간중의 수온은 $21.0\~27.0^{\circ}C$로 자연수온에 비해 높았고,비중(${\delta}_{15}$)은 1.024$\~$1.026으로 비교적 높은 편이었다. 사육기간중의 용존산소는 5.4$\~$7.5 ml/$\iota$ 범위였고, 무기태질소로서 $NH_4^+-N$은 0.07$\~$0.48 ppm, $NO_2^{-}-N$은 0.006$\~$0.33 ppm이었으며, 특히, $NO_3^{-}-N$은 3.89$\~$34.06 ppm으로 매우 높았다. 밀도별 치어의 전장성장은 D20에서 8.17$\pm$0.80 cm로 가장 빨랐고, D10에서 7.72$\pm$0.40 cm로 가장 느렸으나, 밀도구별 성장차이에 대한 유의의 차는 없었다. 밀도별 치어의 체고성장은 D20에서 4.l6$\pm$0.39 cm로 가장 빨랐고, D10에서 3.94$\pm$0.21 cm로 가장 느렸으나, 밀도구별 성장차이에 대한 유의의 차는 없었다. 밀도별 치어의 전장에 대한 체고의 상대성장비는 D10이 b=0.5346으로 가장 높았고, B30이 b=0.5165로 가장 낮았으나, 밀도구간의 유의의 차는 인정되지 않았다. 밀도구별 치어의 생존율은 D10, D20, D30 공히 $90\%$로 높았으나, D40은 $75\%$로 낮은 편이었다. 수용밀도의 지표로서, 안측 체표면적이 수조의 저면적을 덮는율을 구하기 위하여 전장과 체고를 곱한 면적 (X)과 안측 체표면적 (Y)의 상관관계는 Y=0.5994X+0.1840으로 표시되었다. 각 밀도구별 모든 개체의 안측 체표면적이 저면적을 덮는율은, 실험종료시 D10의 1.2배로부터 D4O의 4.1배까지로 나타나, 치어의 고밀도사육이 가능한 것으로 판단되었다.

• 한국어병학회지
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• 제35권2호
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• pp.185-193
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• 2022

This study investigated carnival behavior in the nursery stage of Fenneropenaeus chinensis. In order to suppress the carnival behavior and improve the survival rate, it was examined whether there was a carnivalism inhibitory effect according to the rearing water of shrimp. In addition, their blood physiological changes were observed. As a result, in the experimental group with the size difference of F. chinensis, the survival rate was the highest in the biofloc technology (BFT) rearing water of olive flounder (75%), and in the experimental group without the size difference, the survival rate was the highest in the seawater experiment group (93%). In both experimental groups, rate of carnival behavior was observed to be low in the fed experimental group regardless of the size difference of F. chinensis. As a result of blood cell analysis of F. chinensis according to the rearing water, the percentage of granulocytes was the highest in the BFT rearing water of flounder (75%) and the lowest in the filtered seawater group (66%). The proportion of semi-granulocytes was the highest at 11% in the shrimp BFT rearing water, and the lowest at 7% in the filtered seawater. The proportion of hyalinocytes was highest in filtered seawater (27%) and lowest in flounder BFT rearing water (16%). These results suggest that carnival behavior and blood composition of F. chinensis may be different depending on the conditions of the rearing water in the nursery stage.

• Fisheries and Aquatic Sciences
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• 제14권2호
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• pp.123-129
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• 2011

To determine whether rearing density affects the hypermelanosis on the blind side (ambicoloration) of olive flounders Paralichthys olivaceus, we reared fry with an unpigmented non-eyed (blind) side in duplicate at densities of 150 individuals/$m^2$ (commercial production density: control) and 450 individuals/$m^2$ (high density group) for 90 days in 1-t dark-green fiberglass reinforced plastics (FRP) tank. We recorded feed intake, feed conversion efficiency (FE), growth and survival, and measured the ratios of staining blind-side area (staining area) and ambicolored fish every 30 days. Daily feed intake (DFI), feed conversion efficiency (FE), growth rate, condition factors, and survival rate were calculated at the end of the experiment. Although the FE was higher in the high-density compared to the control, the two density groups showed similar feed intakes, growth, and survival. The ratio of staining area as well as the ratio of ambicolored fish significantly were significantly higher in the high-density group than in the control from days 30 to 60, but significantly increased and evened out by the end of the experiment (P<0.05). In conclusion, we determined that rearing density is not the main cause of the blind-side hypermelanosis, but found that increasing the rearing density can accelerate the ambicoloration in olive flounders.

• 미생물학회지
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• 제8권1호
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• pp.21-34
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• 1970

This experiment was undertaken to examine the injurious environment conditions for occuring of the virus disease, grasserie and cytoplasmic polyhedrosis in rearing of silk worms, to observe of cytoplsamic polyhedrosis diseased silkworms with histological preparation and to define the virus origin on the gattine and the disease of shrinked form after moulting (Okichijimi). The results obtained are as follows. 1) The grasserie in spring season rearing was remarkably infected in highly percent with 20.1 % in high temperature condition during 3rd to 4th instar, the high temperature during 1st to 2nd instar and 5th instar in 16.5% and 16.3%, respectively. In the fall season rearing, the disease was infected by the feeding of soft leaves plot in 5.3% and 4.8%, respectively with significant difference in 5% level, accordingly, it was thought to the nutritional condition is a factor in occuring of the disease. 2) In spring season rearing, the number ofl infected silk worms of cytoplasmic polyhedrosis was increased in the high temperautre and high humidity conditions, and in fall season rearing, order of the low temperature and high humidity plot, first feeding plot and feeded with hard leaves plot were found insome high infected ratio of the disease than control plot. 3) The occuring of cytoplasmic polyhedrosis was observed even in control rearing plot with the examining of anatomical and histological preparation in spring and fall. 4) It was found that the high diseased ratio of the gattine and disease of shrinked form after moulting in 21.8% of control and 93.2% in feeded with inocylated plot in the biosassay of inoculum. It was defined as a virus flacherie acoording to the Danaka and Shimizu's examine method.

• 한국농공학회논문집
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• 제50권1호
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• pp.25-37
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• 2008

When livestock facilities in Korea have been changed larger and denser, rearing conditions have been getting worse and the productivity of animal production have been decreased. Especially in the cold season, the minimized ventilation has generally been operated to save energy cost in Korea resulting in very poor environmental condition and high mortality. While the stability, suitability, and uniformity of the rearing condition are the most important for high productivity, the ventilation configuration is the most important to improve the rearing condition seasonally. But, it is so difficult to analyze the internal air flow and the environmental factors by conducting only field experiment because the weather condition is very unpredictable and unstable as well as the structural specification can not be easily changed by the researchers considering cost and labor. Accordingly, an aerodynamic computer simulation was adopted to this study to overcome the weakness of conducting field experiment and study the aerodynamic itself. It has been supposed that the airflow is the main mechanism of heat, mass, and momentum transfers. To make the simulation model accurately and actually, simplified pig models were also developed. The accuracy of the CFD simulation model was enhanced by 4.4 % of errors compared with the data collected from field experiments. In this paper, using the verified CFD model, the CFD computed internal rearing condition of the mechanically ventilated pig house were analyzed quantitatively as well as qualitatively. Later, this developed model will be computed time-dependently to effectively analyze the seasonal ventilation efficiency more practically and extensively with tracer gas decay theory.

• 한국잠사곤충학회지
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• 제36권2호
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• pp.130-137
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• 1994

천잠의 사육환경을 구명하기 위하여 사료자원, 기상환경 및 사육방법등에 관하여 조사한 결과를 다음과 같이 요약한다. 1. 천잠의 실내사육에 있어 사육온도는 항온보다 변온이 좋은 편이며, 치잠기 25~26$^{\circ}C$, 장잠기 22~23$^{\circ}C$ 범위가, 사육습도는 치잠기 80~90%, 장잠기 60~70% 범위가 적당한 것으로 나타났다. 2. 천잠사육에 있어 광조기는 유충의 성장에 미치는 영향이 크지 아니하였다. 3. 귀잠시기는 빠른것이 늦은 것보다 유충시기에 단축되는 경향이 있으며 질도 양호한 것으로 나타났다. 4. 사료수종은 상수리나무가 밤나무보다 더 적합한 것으로 나타났다. 야생수보다 재배수가 사육성육이 더 좋았다. 5. 천잠을 옥외사육으로 전환하는 시기는 빠를수럭 작황이 불안정해 지는 경향을 보였다.

• 한국가금학회지
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• 제29권4호
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• pp.255-258
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• 2002

본 연구는 성장중인 닭에 있어서 맹장내 혐기성 미생물수와 맹장의 길이와의 관계를 구명하기 위해서 실시되었다. 5주령의 160수의 닭을 80수씩 분리하여 케이지내 사육 (대조구)및 염소 방목장내 염소와 같이 사육 (처리구)의 2처리로 구분하여 실시하였으며, 본 시험기간동안의 사료는 닭의 성장단계에 적합한 시판의 사료를 기초사료로 활용하였다. 시험기간 (5∼8주형)까지의 증체량은 8주령 에서는 대조구가 처리구보다 유의하게 놀았으며(P<0.05), 12주령에서는 처리구가 대조구보다도 유의하게 높았다(p<0.05). 맹장의 길이는 6, 9, 10 및 11주령에 처리구가 대조구보다 유의하게 길었다 (P<0.05). 맹장내 총 혐기성미생물수도 6, 9, 10 빛 11주령에 처리구가 대조구보다 유의하게 많았다(P<0.05). 대조구 및 처리구 함께 맹장의 길이와 증체량간에는 r= 0.816의 상관관계가 인정되었다. 맹장의 길이와 맹장내 혐기성 미생물 수는 대조구 및 처리구 함께 r=0.95이상의 높은 상관 관계가 인정되었다(P<0.01). 결론적으로 성장중인 닭에 있어서 섬유소 함량이 높은 염소의 배설물 섭취 등의 영향에 따른 맹장내 혐기성 미생물 수의 증가가 맹장의 길이 증가에 관계되어진다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 1990년도 춘계 학술대회지
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• pp.26-27
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• 1990