• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.12 s.255
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• pp.1603-1610
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• 2006

In this paper compressive characteristics of composite egg-box panels were investigated and energy absorption was calculated from the nominal stress-strain relations obtained by the compressive tests. Several different stacking sequences and number of plies were introduced for investigation of static compression characteristics and the energy absorption rates of composite egg-box panels. The compressive stress-strain relation and energy absorption of various composite egg-box panels were compared with those of aluminium egg-box panels. From the test results it was found that the fracture behavior of composite egg-box panel was affected by stacking angle causing different local deformation, during lay-up and draping processes and types of prepreg; that is, plain weave carbon/epoxy and 4-harness satin glass/epoxy. The energy absorption capacity of composite egg-box panels were proved to be higher than that of aluminium egg-box panels with low mass.

• Korean journal of applied entomology
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• v.19 no.2 s.43
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• pp.109-112
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• 1980

This study was carried out to investigate the distribution of egg parasitoids from green rice leafhopper, Nephotettix cincticeps Uhler, from the middle of August through the early September in southern rice cultural areas. The results were obtained as follow. 1. Four species of egg parasitoids, Gonatocerus sp. A and B, Paracentrobia andoi and Anagrus sp. are newly recorded from the eggs of green rice leafhopper. 2. Egg parasitism rates of Gonatocerus sp. were varied from $41.0\~73.9\%$ on an egg mass basis and from $29.7\~49.0\%$ on basis of egg. Percent parasitism rates by Paracentrobia andoi were $0\~9.7\%$ on an egg mass basis and from $2.1\~12.6\%$ on basis of egg. Gonatocerus sp. was dominant egg parasitoid in the parasitism rate than Paracentrobia andoi.

• Korean journal of applied entomology
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• v.41 no.3
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• pp.225-231
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• 2002

The entomopathogenic nematodes, Steinernema carpocapsae All strain (ScA), S.glaseri NC strain (SgN) and H. bacteriophora NC 1 strain (HbN), were evaluated for the effects on egg mass formation by the northern root-knot nematode, Meloidogyne hapla in pot experiment using tomato. In the first experiment, 2.5$\times$10$^{5}$ infective juveniles (Ijs) of entomopathogenic nematodes were inoculated to 100 g of the soil infected with ca. 450 Ijs of M. hapla/100 ㎤ in 150 $mell$ container. The number of egg mass was significantly decreased to 9.4-36.5 in ScA, to 5.7-24.7 in SgN and to 11.2-16.0 in HbN treatments compared with 62.5 in M.hapla alone. In the second experiment, ScA and S.carpocapsae Pocheon strain (ScP) and SgN and S.glaseri Dongrae strain (SgD) were treated to 350 g of the soil infected with 100, 200 M.hapla larvae/100 ㎤ in 450 $mell$ container The entomopathogenic nematodes were inoculated at the rate of 2,020 Ijs and 1.6$\times$105 Ijs in 350 g soil. The number of egg mass of M.hapla were significantly decreased in the entomopathogenic nematode treatments compared with M.hapla alone although no differences were observed among Steinernema species, strains, or infection concentrations. Treatments of entomopathogenic nematodes 3 days before M.hapla inoculation were more effective on reduction of egg mass formation than those of 3 days after M.hapla treatments. Growth of tomato was not affected by entomopathogenic nematode treatments.

• Journal of Aquaculture
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• v.9 no.4
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• pp.345-351
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• 1996

Mass production of resting egg of the rotifer, Brachionus plicatilis was carried out in 1 $m^3$ tank for L-type rotifer and in 1 $m^3$ and 4 $m^3$ tank for S-type rotifer. L-type rotifer was fed on concentrated Chlorella + baker's yeast and only baker's yeast for 15 days. S-type rotifer was fed on concentrated Chlorella in 1 $m^3$ tank for 7 days and frozen Chlorella + baker's yeast in 4 $m^3$ for $6\~8$ days. Total number of resting egg and number of resting egg from $10^8$ rotifers and 1 g dry weight diet for L-type rotifer fed on Chlorella + baker's yeast were $54.5{\times}10^6$ eggs, $30.5{\times}10^6$ eggs and $100{\times}10^3$ eggs, respectively. These were higher than those of rotifer fed on baker's yeast only. Total number of resting egg and number of resting egg from $10^8$ rotifers and 1 g dry weight diet for S-type rotifer fed on concentrated Chlorella in 1 $m^3$ tank were $50\~104{\times}10^6$ eggs, $47\~82{\times}10^6$ eggs and $136\~260{\times}10^3$ eggs, respectively. In 4 $m^3$ tank with frozen Chlorella + baker's yeast, these were $149\~567{\times}10^6$ eggs, $36\~123{\times}10^6$ eggs and $131\~338{\times}10^3$ eggs, respectively. This result suggests that S-type rotifer are better than L-type rotifer for the mass production of resting egg of the Korean rotifer.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.1
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• pp.31-37
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• 2021

The mass production of fertilized eggs of the convict grouper Hyporthodus septemfasciatus was studied from 2013 to 2020 for industrial aquaculture. The experiment was divided into two groups. Group 1 broodstock was raised from wild-caught fry and used from 2013 to 2020. Group 2 broodstock was raised from artificially propagated fry and used from 2019 to 2020. Males used to collect sperm for artificial insemination weighed more than 7 kg. The effects of various hormones on artificial ovulation were investigated from 2013 onward. Among these, luteinizing hormone-releasing hormone analogue (LHRHa) at 100 ㎍/kg body weight showed the most effective results and was used for artificial egg collection from 2014 onward. In Group 1, the average total egg production per year, average egg production per individual, fertilization rate, and hatching rate were 26,143 mL, 609.7 mL, 93.3%, and 91.8%, respectively, and in Group 2, were 2,750 mL, 316.5 mL, 92.1%, and 90.4%, respectively. Based on these results, we showed that a large number of fertilized eggs for artificial seeding could be produced consistently. Moreover, the mass production of fertilized eggs in Group 2 establishes a foundation for the complete aquaculture cycle of H. septemfasciatus.

• International Journal of Industrial Entomology and Biomaterials
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• v.46 no.2
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• pp.55-59
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• 2023

One of the necessary conditions for the mass production of the edible insect, the white-spotted flower chafer Protaetia brevitarsis seulensis (Kolbe), is to breed a strain with excellent egg-laying ability. To identify external morphological traits related to egg-laying ability, we investigated the effects of the weight, length, and width of female adults on egg production. Correlation and multiple regression analyses revealed a positive correlation between the weight of female adults and egg production. This study suggests that selection of heavier females is a good strategy for breeding strains with superior egg-laying characteristics. The results of this study will serve as important foundational data for future breeding of superior strains.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.4
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• pp.518-522
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• 2004

This experiment was conducted to investigate the effects of different levels of dried leftover food (DLF) in the diet on feed utilization and egg-laying performance of hens. One hundred sixty-eight, 18 week old Tetra brown commercial layers, were assigned to 7 treatments in a completely randomized design. Each treatment has four replications per treatment with six animals per replication. All the experimental animals were fed diets for 7 weeks. The treatments included 1) control group without DLF, 2) diet with 10% DLF, 3) diet with 20% DLF, 4) diet with 30% DLF, 5) 10% higher protein level of diet with 10% DLF, 6) 20% higher protein level of diet with 20% DLF and 7) 30% higher protein level of diet with 30% DLF. Average daily feed intake (ADFI) tended to be improved with DLF feeding. ADFI of group fed diets with 20% was significantly higher than that of control (p<0.05). Feed conversions of DLFfed groups were higher than that of control. Egg production tended to be higher in groups fed diets with 10% DLF than control diet without significant differences (p>0.05). However, those of groups fed diets containing 20 and 30% DLF were lower than that of control. Supplementing protein source to DLF-containing diets improved egg production (p<0.05). Increasing level of DLF in the diet for layer decreased egg weight and egg mass compared to control without significant differences (p>0.05). Protein supplementation to DLF-containing diets increased egg mass without significant difference (p>0.05). The range of egg cholesterol concentration of DLF-fed groups was 11.94-14.10 mg/g while that of control group was 12.31 mg/g although there was no significant difference among treatments (p>0.05).

• Animal Bioscience
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• v.34 no.5
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• pp.886-894
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• 2021

Objective: An experiment was conducted to study the effect of graded concentration of digestible lysine (dLys) on performance of layers fed diets containing sub-optimal level of protein. Methods: Five diets were formulated to contain graded concentrations of dLys (0.700%, 0.665%, 0.630%, 0.593%, and 0.563%), but similar levels of crude protein (15% CP), energy (10.25 MJ ME/kg) and other nutrients. A total of 3,520 hens (26 wk of age) with mean body weight of 1,215+12.65 g were randomly divided into 40 replicate groups of 88 birds in each and housed in an open sided colony cage house. Each diet was offered ad libitum to eight replicates from 27 to 74 wk of age. The performance was compiled at every 28 d and the data for each parameter were grouped into three phases, that is early laying phase (27 to 38 wk), mid laying phase (39 to 58 wk), and late laying phase (59 to 74 wk of age) for statistical analysis. Results: Egg production, egg mass and feed efficiency (feed required to produce an egg) were significantly improved by the dLys level during the early and mid laying phases but not during the late phase. Whereas feed intake was significantly reduced by dLys concentration during mid and late laying phases but not during early laying phase. The egg weight was not affected by dLys concentration in any of the three phases. Conclusion: Based on best fitted statistical models, dietary requirements of dLys worked out to be 0.685%, 0.640%, and 0.586% during early phase, mid phase, and late egg laying phase, respectively. The calculated requirement of dLys for the respective production phases are 727 mg/b/d during the early and mid laying phases and 684 mg/b/d during the late laying phase in diets containing 15% CP.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.12
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• pp.1799-1803
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• 2003

The possibility of lycopene affecting egg yolk pigmentation was studied with lycopene diets containing 0, 4, 8, and $12{\mu}g/g$ meal, respectively. The addition of lycopene above $4{\mu}g/g$ meal significantly improved yolk color after four days of supplementation. The transfer of lycopene into egg yolk was confirmed by thin layer chromatography, and high-performance liquid chromatography-mass spectrometry (HPLC-MS). The deposition rate of lycopene into egg yolk was approximately 2%, which was quantitatively determined using a HPLC with a UV detector. The result indicates that lycopene is a good candidate for egg yolk pigmentation and for making functional eggs.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2000.11a
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• pp.70-72
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• 2000

The Effects of Dietary Supplemental Charcoal Extract (CE) were examined on performance of 19-week-old ISA Brown hens for 12weeks. Four hundred and fifty were randolmy assigned to 0, 0.025, 0.05, 0.075, 0.1% dietary CE, respectively with five replicates of 18 hens per pen. Basal diets contained 17.5% CP and 2,800 ME. Egg production egg weight, feed conversion(FC), and egg qualities were measured in every four weeks. Egg production and FC was slightly improved in 0.05% supplemental CE group compared to that of other treatments, but was not signhificant different. Average egg weight was significantly higher in 0.025% and 0.1% than other treatments(P<0.05). Total egg mass tended to be higher in 0.05% supplementation. Daily feed intake increased in 0.1% supplementation than the others, but was not statistically different. Eggshell breaking strength and Haugh unit were tended to be higher in 0.05% supplementation. There were no significant difference in eggshell thickness and yolk color of all treatments.