• International Journal of Industrial Entomology and Biomaterials
• /
• v.3 no.2
• /
• pp.135-139
• /
• 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.

• Journal of Aquaculture
• /
• v.14 no.1
• /
• pp.29-33
• /
• 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.

• Journal of Aquaculture
• /
• v.1 no.1
• /
• pp.13-24
• /
• 1988

In order to investigate a reasonable rearing density and the possibility of high-density rearing, flounder, Paralichthys olivaceus, juveniles of 2.53$\pm$0.24 cm in total length and 1.12$\pm$0.12 cm in body height were used in this study. The initial rearing density of them was 10 (D10), 20 (D20), 30 (D30) and 40 (D40) individuals per 137.75 $cm^2$ of bottom area, respectively. Ranges of water temperature and specific gravity during the rearing period of 65 days were $21.0\~27.0^{\circ}C$ and 1.024$\~$1.026, respectively, showing relatively higher values than that of natural sea water. Dissolved oxygen during the rearing period was 5.4$\~$7.5 ml/$\iota$ and inorganic nitrate was 0.07$\~$0.48 ppm in $NH_4^+-N$, 0.006$\~$0.33 ppm in $NO_2^{-}-N$ and 3.89$\~$34.06 ppm in $NO_3^{-}-N$. Growth in total length and body height of the juveniles in four rearing density at the end of the experiment was 8.17$\pm$0.80 em and 4.16$\pm$0.39 em, the highest in D20 and 7.72$\pm$0.40 cm and 3.94$\pm$0.21 cm, the lowest in D10. Significant differences, however, were not recognized between the slope values of growth regressions in four rearing density. Slope values of the relative growth between total length and body height of the juveniles in four rearing density were 0.5346, the highest in D10 and 0.5165, the lowest in D30, but there were no significant differences in those values. Survival rate of juveniles at the end of the experiment was $90\%$ in D10, D20 and D30, but that of D40 was $75\%$. The relationship between total length X body height (X) and body surface area of ocular side (Y) to calculate the rate of Y to bottom area in rearing tank (covering rate) as an indicator of rearing density was expressed by a linear regression, Y=0.5994X+0.1840. Covering rate in four rearing density at the end of the experiment was ranged 1.2$\~$4.1 times. Judging from the covering rate above 4 times, it seems to be possible rearing the flounder juveniles in high-density.

• Journal of fish pathology
• /
• v.35 no.2
• /
• pp.185-193
• /
• 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
• /
• v.14 no.2
• /
• pp.123-129
• /
• 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.

• Korean Journal of Microbiology
• /
• v.8 no.1
• /
• pp.21-34
• /
• 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.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.50 no.1
• /
• pp.25-37
• /
• 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.

• Journal of Sericultural and Entomological Science
• /
• v.36 no.2
• /
• pp.130-137
• /
• 1994

This experiment was conducted to evaluate the reasonable rearing technique of Japanese oak silkworm under the different rearing condition as environment, feeding materials and rearing methods. The results are summerized as follows. The optimum temperature for the indoor rearing of Japanese oak silkworm was 25~26$^{\circ}C$ a in young silkworm and 22~23$^{\circ}C$ in grown silkworm, and generally in the condition of variable day/night temperature the growth of silkworm was faster than in that of constant temperature. The optimum relative humidity for it's growth was 80~90% at young silkworm stage and 60~70% at grown silkworm stage. The photoperiod was not affected to the growth of Japanese oak silkworm. The earlier brushing, the shorter the young silkworm stage, and the cocoon quality improved compared to the later brushing time. As a feeding materials aok (Auercus acutissima Crruthers) leaves were better than those of chestnut tree (Castanea Crenata Siebold & Zuccarini) and feeding value of cultivated oak tree leaves was better than that of natural oak tree leaves. The moving time when revealed the better cocoon production of Japanese oak silkworm from indoor condition to outdoor was 15 days after hatched, and the cocoon production was decreased by the earlier moving to outdoor.

• Korean Journal of Poultry Science
• /
• v.29 no.4
• /
• pp.255-258
• /
• 2002

A study was conducted to investigate the correlation of cecal anaerobic bacterial counts with the cecal length in growing chicks. Half of 160 chicks of five weeks old were housed in cages and the remainings were kept with goats in free-range and allowed to have free access to goat's feed and faeces. All the experimental birds were fed ad libitum on a commercial chick formula diet during the period of 5 to 12 weeks of age. Body weight was larger in birds reared in the cage than in those reared on the field at 8 weeks of age (P<0.05), but vice versa at the end of experiment (P<0.05). The cecal length was longer in field-rearing than in cage-rearing at 6, 9, 10 and 11 weeks of age (P<0.05). The cecal length was correlated with body weight gain in both rearing groups (r=0.816 f3r cage-rearing, r=0.816 for field-rearing). The cecal anaerobic bacterial counts were significantly higher in field- rearing than in cage-rearing at 6, 9, 10 and 11 weeks of age (P<0.05). The cecal length was highly correlated with cecal anaerobic bacterial counts in cage- (r=0.9549) and field-(r=0.9866) rearing. It is concluded that the correlation of increase cecal length with increased cecal anaerobic bacterial counts ted a libelous of goat's faeces in growing chicks.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 1990.05a
• /
• pp.26-27
• /
• 1990