• Journal of Ginseng Research
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• v.13 no.2
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• pp.174-177
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• 1989

The ovipositional preferences of Holotrichia morosa were investigated to defermine several environmental factors related to its incidence in ginseng fields. H. moroia paid no eggs in naked soil without ground color plants, and shouted ovipositional preference among weed plants in the order to Aurmisin prinrcps var oripntnlis, Epigrren canadensis Diuitarin sanguinalis, and Porttulaca oleracea. More oviposition was observed in the denser vegetation of D. sanguinalis and in soft soil. The egg-laying females were seldom attracted to fresh rice straw mulched on soil surface or decayred rite straw mixed into soil. The number of eggs laid by a female decreased considerably when the soil moisture content was below 5% or above 35%.

• Korean Journal of Poultry Science
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• v.23 no.2
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• pp.85-98
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• 1996

Results of experiments on the nutrient requirements and feeding system of broiler breeder hens were reviewed, and daily requirements of energy and protein were calculated using the prediction equations reported by Scott(1977) and NRC(1981). The experimental reports on daily ME needs of broiler breeder hens were ranged from 400 to 450 kcal, however, the ME needs of caged hens were 92~93% to those of floor-housed hens due to the difference of ME need for activity. The ME needs of broiler breeders decreased with increasing environmental temperature corresponding to a drop of 25 kcal per day for each 5˚C rise. About 80~90% of the daily ME needs were used for body rnaintenance and activity of hens. Experimental results on daily protein needs of broiler breeder hens were ranged from 18 to 22 g, however, calculated protein needs decreased as the BW gain and eggmass output decreased after peak production, and about 60~65% of the daily protein needs were used for egg production. In the current practice, broiler breeder hens are restricted in feed, and consume their daily allowance in the first 2 to 6 h after dawn. The results suggest that eggshell quality can be significantly improved in hens fed during the afternoon when shell calcification is initiated, with no adverse effect on laying rate and fertility of eggs.

• Journal of Sericultural and Entomological Science
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• v.6
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• pp.28-30
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• 1966

The aim of this experiment was to investigate the method of discrimination of male and female depending upon the specific gravity of pupa in silkworm varieties which are being recommended in Korea at present. The results obtained are as follows: 1. The specific gravity of silkworm pupa existed between 1,000 and 1,100. 2. Female pupae went to the bottom of salt water(NaCl), around 1,020 of specific gravity, while male pupae came near to the surface of salt water. 3. Salt water of around 1,020 specific gravity was not harmful to the pupa, egg laying ability and moth emerging ability. 4. The effect of salt water on the other useful characters will be assigned to the next chance, and also the device of cocoon cutting machine is being studied.

• International Journal of Industrial Entomology and Biomaterials
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• v.15 no.2
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• pp.107-114
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• 2007

We investigated mating conditions of photoperiod, illumination and temperature during mating periods, care temperature of queen before mating, mating period and number of queen per mating cage to improve mating rate of Bombus ignitus. Among photoperiodic regimes of 12L, 14L and 16L during mating periods, queen mated at 14L showed better results than at 12L and 16L in egg-laying characteristics and colony development. In case of illumination during mating periods, intensity of 1000 lux was more effective than at intensity of 100 lux and 2000 lux in mating B. ignitus queen. Mating temperature and care temperature of queen before mating favorable for B. ignitus queen were $22-25^{\circ}C$ and $19^{\circ}C$, respectively. The period need to mating B. ignitus queen was 3 days, and the number of queen suitable per mating cage of $55{\times}45{\time}65\;cm$ was 30.

• Journal of Environmental Science International
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• v.29 no.7
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• pp.789-792
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• 2020

The present study was investigated the oviposition characteristics of Protaetia brevitarsis seulensis with a focus on winter larvae to improve the utilization of insect resources. The average oviposition tendency and average cumulative number of eggs laid during a 7-week period were measured in adults emerging from larvae that had hibernated for 4 months in five farmhouses. The study covered five zones: Gimje, Jangsu, Wanju, Iksan and Yeoju. The average oviposition tendency over a 7-week period showed increased egg laying between 2 to 3 weeks and 5 to 6 weeks. Overall, it was found that the average cumulative number of eggs laid during the 7-week period was initially low and increased proportionally with time. Our results suggest that using adults that have emerged from hibernated larvae is effective in increasing the oviposition rate and utilization of the insect.

• Korean Journal of Veterinary Research
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• v.56 no.3
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• pp.167-176
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• 2016

We investigated whether maternal antibodies (mAbs) elicited by dams immunized with recombinant vaccine candidates against avian pathogenic Escherichia coli (APEC) can passively confer protective immunity to chicks. In the present study, pBP244 plasmids carrying selected antigens of APEC were transformed into Salmonella Typhimurium JOL912, which was used as a vaccine candidate against APEC. The hens were immunized with the vaccine candidates using prime or booster doses. The levels of IgG and sIgA specific to the selected antigens increased significantly following prime immunization. To evaluate the persistence of passively transferred mAbs, the levels of IgY and IgA were determined in egg yolks and whites, respectively. The eggs from the immunized group showed consistently increased levels of IgY and IgA until week 16 post-laying (PL) and week 8 PL, respectively, relative to the control group. The presence of mAbs was observed in chicks that hatched from the hens, and titers of plasma IgY were consistently raised in those from the immunized hens by day 14 post-hatching. Further, chicks from the immunized hens were protected from challenge with a virulent APEC strain, whereas those from non-immunized hens showed acute mortality.

• Journal of the Korean Applied Science and Technology
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• v.25 no.2
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• pp.196-204
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• 2008

Hemp seed oil and evening primrose oil were incorporated into the diets of laying hens for 5 weeks and the level of gamma fatty acid in the eggs that the treated hens laid was then evaluated. Hens were fed corn-soybean based diets that contained 5% tallow, 5% corn oil (CO), 5% hemp seed oil (HSO), or 5% evening primrose oil (EPO). The hemp seed oil and evening primrose oil influenced the amount of gamma linolenic acid found in the eggs through blood. The level of gamma linolenic acid in the plasma was significantly higher in hens that received the HSO and EPO diets than in those that received the tallow and CO diets. The HSO and EPO diets led to a 1.09% and 4.87% increase in egg gamma linolenic acids, respectively, when compared with eggs produced by hens treated with tallow and CO. Taken together, these data demonstrate that healthy eggs with increased gamma linolenic acids can be generated by minor diet modifications when hemp seed oil or evening primrose oil is included in the hen diet.

• Journal of Animal Science and Technology
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• v.47 no.4
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• pp.547-554
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• 2005

An experiment was conducted to investigate the dietary effects of a transgenic Aspergillus oryzae(AO) culture on the performance, egg quality and intestinal microflora of layers. A total of 840 Hy-line Brown layers of 39wks old were assigned to one of the following 7 dietary treatments: control(C), C+0.2% AO culture, C+0.5% AO culture, C+0.2% transgenic AO culture, C+0.5% transgenic AO culture, C+0.2% transgenic mutant AO culture, and C+0.5% transgenic mutant AO culture. The transgenic AO was made by inserting Salmonella gallinarum gene to AO. And the transgenic mutant AO was made by inserting Salmonella gallinarum gene to mutant AO which was mutated by UV irradiation. Each treatment was replicated six times with 20 birds housed in 2 bird cage. Twenty birds units were arranged according to completely randomized block design. Feeding trial lasted for 8wks under 16 hour lighting regimen. Laying performance and egg quality were significantly(P<0.05) affected by the treatments. Transgenic AO culture supplementation at the level of 0.2% significantly increased egg production, while its egg weight was significantly decreased compared to that of the control. Feed intake and feed conversion ratio(FCR) were not significantly different among the AO treatments and the control. The eggshell strength of the AO treatments was significantly higher than that of the control. Transgenic mutant AO culture supplemented at the level of 0.5% significantly increased egg yolk color. Intestinal microflora were significantly(P<0.05) affected by the treatments. The cfu of Lactobacilli spp. significantly increased and those of Salmonella species and E. coli decreased in the AO treatments. The transgenic AO and transgenic mutant AO culture were more effective than the AO culture in reducing the cfu of Salmonella species and E. coli. It is concluded that supplementation of the transgenic AO culture at the level of 0.2% could be recommended for the improvement of egg production. Supplementation of transgenic AO or transgenic mutant AO culture at 0.2% level effectively controlled intestinal Salmonella species population.

• Korean Journal of Poultry Science
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• v.30 no.4
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• pp.245-251
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• 2003

Three experiments were conducted to investigate the effect of feeding yeast accumulated transgenic ferritin(FRT, Saccharomyces cerevisiae) as a probiotic on the performance, iron contents in the liver, spleen, bone and yolk of laying hens and broiler chicks. Effects of feeding FRT were compared with that of feeding wild-type yeast(W0) and yeast grown on 20 mM ferric citrate-added medium (W20). In Expt 1, to investigate the effect of feeding yeast (control, W0 FRT) on performance and iron content of organs of broiler chicks which were fed basal diet supplemented with 75mg/kg iron(Fe75) or not (Fe0), three hundred sixty one-day-old male broiler chicks were fed a corn-sov based diet for five weeks. Weight gain, feed intake and feed conversion were measured weekly. In Expt 2, fifteen 33-week-old ISA Brown laying hens were placed in individual cages and were fed control, W0 and FRT diets for Four weeks. In Expt 3, twenty four 45-week-old ISA Brown laying hens were placed in individual cages and were fed a basal diet for a week. Then, experimental diets (control, W0, W20, FRT) were fed for three weeks. Iron contents in the liver, heart, spleen and tibia were determined at the end of all experiments. Iron content in yolk was measured weekly (expt 2, 3). The level of yeast added and iron concentration of FRT were $1{\times}10^8$cfu/kg diet and 500 mg/kg cell (DM) respectively in Expt 3, yeast was supplemented at $2{\times}10^{10}$cfu/kg diet and the iron content of FRT was 1000mg/kg cell (DM). In Expt 1. birds fed Fe75 showed significantly higher weight gain compared with Fe0 (P<0.05). However, weight gain and feed intake of birds fed FRT was significantly lower than control (P<0.05). In Expt 2, the iron content of the liver was decreased in the FRT treatment (P<0.05). In Expt 3, iron concentration of the liver and spleen tended to be increased by feeding FRt. However, the iron content of the tibia tended to be decreased in the FRT treatment. These results suggest that feeding FRT as a probiotic cannot improve performance and iron content in organs of broiler chicks and laying hens.

• Journal of Sericultural and Entomological Science
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• v.4
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• pp.41-46
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• 1965

Author investigated the effects of a grate type mounting on. the pupae, moth and deposit of silkworm eggs. The results are as follows. 1) The grate type mounting was more useful for the silkworms to spin the cocoons transversely than the other type. 2) Many abnormal pupae appeared in the control, and in next generation all the silkworm characters of them were poor. 3) The fact which many dead pupae occurred in the control seems to be that the cocoons spun vertical1y did harm to the physiological reactions of the pupae. 4) The moth rate emerging out of the cocoons was higher in the grate type mounting than in the control. 5) Many moths which laid normal eggs were in the grate type mounting, and also laid a lot of eggs. Therefor, author made an infference that the grate type mounting had accelerated the laying eggs. 7) The total weight of eggs produced from 1000 cocoons was heavier in the grate type mounting(index=100) than in the control (index=85). As shown in table of analysis of vanriace, above phenomenon might be relative with one of the reasons why the cocoon spun transversely could be more produced in the grate type mounting than in the control. 8) Even though the grate type mounting costs higher than the other one, it may be available because the egg weight per unit was considerably heavier in its treatment. So the cost of egg production will become cheaper.