• Journal of Sericultural and Entomological Science
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• v.51 no.2
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• pp.89-94
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• 2013

The aim of the present study is to investigate food consumption, hatching periods, adult mortality, the mean number of hatchlings and ovipositional trend of Gryllus bimaculatus De Geer. The rearing and experiments were conducted in the rearing room ($28{\pm}2^{\circ}C$, $60{\pm}10%$RH). As the adult rearing density increased from 50 to 400, it did not affect the average daily food consumption of adult crickets which was $0.067{\pm}0.008$ g a day. However, the daily radish consumption decreased from 0.128 to 0.068 g per day. 95.8% of eggs hatched by the sixth day after the beginning of hatching. The average mortality of the adults gradually increased, and reached 93.9% by the 8th week. Total number of hatchlings per female was $172.2{\pm}10.6$ ($mean{\pm}SD$) in 200 females rearing cages, which was noticeably less than $248.8{\pm}17.8$ ($mean{\pm}SD$) in 100 females rearing cages. Sex ratio of the crickets given in the rearing cages did not affect both the number of hatchlings and ovipositon rate. Oviposition rate periodically fluctuated as progressed, and it reached 81.5% of the total oviposition by the $3^{rd}$ week since the beginning of ovipoisiton.

• Korean Journal of Poultry Science
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• v.33 no.4
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• pp.317-321
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• 2006

The effects of dietary humic substances (HS) on egg Production and egg Quality were studied using 252(55-wk old) ISA brown laying hens. laying were divided into 21 groups of 12 hens each and seven groups (experimental units) were assigned to 1) CON (basal diet), 2) HS5 (basal diet 4- 5% humic substances) or 3) HS10 (basal diet +10% humic substances) in a completely randomized block design. Hens had free access to diets and water fur 6 wk. Egg Production and egg quality were monitored over the 6-wk Period. Results showed that 10% dietary HS decreased egg Production and yolk diameter (P<0.05) compared to CON. Egg weight and yolk cole. were improved (P<0.05) in HS10 compared to CON. Egg shell breaking strength was increased significantly (P<0.05) when hens were fed HS5 diet compared to the others. There were no effects of treatments on egg shell thickness, yolk index, albumen height and Haugh nit. The results suggest that the dietary supplementation of HS at 5% or 10% decreases egg Production, but HS at 5% can increase egg shell breaking strength. Hens fed 10% HS could increase egg weight and yolk color and decrease yolk diameter.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2005.11a
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• pp.74-75
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• 2005

In order to evaluate dietary brown seaweed and vancomycin on the performance, layers(Isa brown) were fed on basal diet and diets containing 2.0% of brown seaweed or 10ppm vancomycin. Brown seaweed diet significantly increased(p<0.01) nitrogen balance in layer, while excretion of uric acid nitrogen and metabolizable energy utilization were not different among diets. Layer consumed more the brown seaweed diet(p<0.05). Egg production were significantly different by diets but reduced(p<0.0001) with the experimental period passed. Layer fed brown seaweed diet gave thicker shell eggs, higher Haugh unit and higher egg white CuZnSOD activity compared with those in basal diet. Also, Brown seaweed diet increased MnSOD activity in erythrocyte cytosol and peroxidase in plasma, but decreased peroxide level in plasma, and increased proliferation of PBMC stimulated with PHA-P The result indicated that brown seaweed 2.0% diet in layer improved egg quality and performance due to increased protein synthesis which were related to regulation of antioxidant system and immune cell function in blood.

• Korean Journal of Poultry Science
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• v.30 no.4
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• pp.281-287
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• 2003

This experiment was carried out to study the effect of dietary Monascus culture on the cholesterol contents of egg yolk, muscle and serum of layers with 180 Isa-Brown laying hens for 10 weeks. Control group(C) was fed the commercial laying hen diet and 2.67(T1), 5.33(T2) and 8.00(T3)% of Monascus culture which contained 0.6% monacolin-k added to control diet so as to supply the monacolin-k 20(T1), 40(T2) and 60(T3) mg respectively, per hen-day with 125g diet. Hen-day egg production and average egg weight were not affected by the dietary Monascus culture, but feed intake and feed conversion per kg egg were significantly decreased(P<0.05) as the dietary Monascus culture increased. Cholesterol contents of egg yolk measured 4~5 weeks after feeding the Monascus culture and those of thigh meat measured at the end of experiment were significantly decreased(P<0.05) as the dietary Monascus culture increased. Average cholesterol contents of serum showed a trend to decrease as the dietary Monascus culture increased without significant difference.

• Korean Journal of Poultry Science
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• v.29 no.2
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• pp.117-124
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• 2002

Betaine functions as an osmoregulators in the cells and its inclusion in diet can spare the choline and carcass fat reduction in chicken. Thus, two hundred eighty eight laying hens were fed with 0, 500, 1,000, 2,000 ppm of betaine from seventy eight to eighty six weeks of age during the environmentally high temperature stress. Com and soybean basal diets contained 2,800 kcal/kg ME and 16% CP. Egg production, feed intake, and feed conversion were examined for eight weeks. Egg quality characters, serum cholesterol, liver betaine, and lower ileal osmolality were measured at the end of experiment. Egg Production rates of hens fed with 500 or 2,000 ppm of betaine were 75.06 and 75.02%, respectively and tended to increase compared to the control. The feed conversion(FCR) of these treatments was significantly(P<0.05) improved compared to that of control although it did not significantly differ in the e99 Production rates between 500 and 2,000 ppm of betain groups. Eggshell breaking strength of hens fed betaine was significantly(P<0.05) higher than those of control. However, betaine supplements did not influence to improving the albumen height and Haugh unit. Liver betaine in hens fed with betaine was linearly increased unto 2,000 ppm. The birds fed with 2,000 ppm betaine showed significantly(P<0.05) higher in the liver betaine than the control birds. Total cholesterol and triglyceride tended to be increased by dietary betaine supplement. The lower ileal osmolality in betaine supplement group tended to be slightly decreased. As a result, dietary betaine supplement tended to improve the egg Production and eggshell Quality in laying hens during heat stress.

• Korean journal of applied entomology
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• v.57 no.4
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• pp.373-379
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• 2018

This study investigated the developmental and ovipositional characteristics of Protaetia brevitarsis individuals that were fed with fermented mulberry sawdust. The developmental periods of larvae were 164.0, 73.3, and 64.8 days at 25, 28, and $30^{\circ}C$, respectively. The maximum larval weight was 2.94 g at $25^{\circ}C$, and the weight of larvae decreased as temperature increased. The average weight of female adults were 0.94, 0.51, and 0.54 g at 25, 28, and $30^{\circ}C$, respectively. The weight of male adults was higher than that of females. The addition of 10% or 30% wheat bran to the fermented mulberry sawdust increased larval weight. It was possible to sell larvae from 75 days after mass rearing, when the cumulative rate of larvae that were heavier than 2.5 g was approximately 75%. The average number of eggs per female was 83.2 at $25^{\circ}C$, and this was the highest in the 5th week. Most of the eggs (73%) were oviposited between 3 and 8 weeks after adults emergence.

• Journal of Life Science
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• v.34 no.2
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• pp.122-127
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• 2024

This study investigated the reproductive ecology and spawning of Hoplobrotula armata on the coast of Jejudo Island. Samples were collected from February to December 2019 and February to December 2020, with a total of 2,634 samples. The results of the investigation showed that total length (TL) ranged from 22.0 cm to 68.8 cm, and the body weight (BW) ranged from 66.5 g to 3,553.9 g. According to the development process of gonads and the gonadosomatic index (GSI), the spawning period of H. armata was from July to October. The relationship between TL and BW was BW = 0.0024TL^3.3278 in females and BW = 0.0035TL^3.2162 in males. The sex ratios of surveyed female to male H. armata was 1:0.71, with more females. At 50%, 75%, and 97.5%, the group maturities of H. armata were as follows: Females, 39.9 cm, 42.7 cm, and 49.4 cm; males, 37.6 cm, 40.4 cm, and 46.9 cm, respectively. According to monthly GSI and gametocyte (ovarian, testis) development stage observations of H. armata on the coast of Jejudo Island, they spawn once a year and are presumed to be summer spawners.

• Korean Journal of Poultry Science
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• v.17 no.3
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• pp.179-191
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• 1990

In order to study the effects of supplementation of live yeast(Saccharomyces cerevisiae) on the performance of laying hens, five experiments were conducted. Two experiment were conducted during summer period, one with 37 wk old Dekalb-Delta strain laying birds(Exp. 1) and the other one with 100 wk old molted Nick Chick Brown laying birds(Esp.2) . In each experiment, 240 birds were divided into 12 groups of 20 birds each and randomly distributed. Each of the two experimental diets(Control 71 and 0.05% live yeast supplemented 72) was fed to 6 groups for 4 wks in Exp.1 and 3 wks in Exp.2. Three experiments were conducted during winter period, Exp.2 with 54 wk old Hy-Line strain laying birds, Exp.4 with 52 wk old Hy-Line strain laying birds, and Exp.5 with 36 wk old broiler breeder(Indian River strain). In each experiment, 540 birds were divided into 18 groups of 30 birds each and randomly distributed. Each of the 3 experimental diets(Control：$T_1$0.05% live yeast supplemented：$T_2$ and 0.1% live yeast supplemented ： T$_3$) was fed to 9 groups for 6 wks in Exp.3, 9 wks in Exp.4 and 4 wks in Exp.5. In Exp.4, Latin Square design was employed to determine the effects of switching feeds at 3 wk intervals. All hens were housed in cages of commercial farm and experimental diets were made with commercial layer feeds. In Experiment 1, egg production was significantly(P＜0.05) higher in $T_2$. Feed intake was significantly (P＜higher in 72 at 1st wk but 4 wk average was not significantly different. Feed efficiency was significantly(P＜0.01) better in 72 at End wk but 4 wk average was not significantly different. Other parameters, such as weight, soft egg production, cracked egg production and mortality were not significantly different. In Experiment 2, egg production was significantly(P＜0.05) higher in $T_2$. Feed efficiency was significantly (P＜0.05 and P＜0.01) better at End wk and 3rd wk but 3 wk average was not significantly different. Soft egg production was significantly(P＜0.05) higher in 72. Other parameters were not significantly different. In Experiment 3, egg productions were significantly(P＜0.05) different among treatments ： $T_3$ was higher than $T_1$ and $T_2$ was higher than $T_1$. Egg weight of $T_1$ and $T_2$was significantly(P＜0.05) heavier than $T_3$. Feed intake of $T_2$ and $T_3$ was significantly(P＜0.05) higher than $T_1$ at 6th wk but overall average was not significantly different. Soft egg production were significantly(P＜0.01) different among treatments：$T_1$ was higher than $T_3$ was higher than $T_2$. Feed efficiency cracked e99 Production and mortality were not signifcantly different. In Experiment 4, egg production tended to increase as the level of live yeast supplementation increased but they were not statistically different. In Experiment 5, egg production of broiler breeders of $T_3$ was significantly(P＜0.01) higher than $T_1$. Feed intake of $T_3$ was significantly(P＜0.05) greater than $T_1$ and $T_2$ at 3rd wk but overall average was not significantly different. Fertility and hatchability tended to be higher in the supplemented groups than in the control.

• Korean Journal of Poultry Science
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• v.37 no.1
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• pp.63-68
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• 2010

This experiment was conducted to investigate the effects of dietary supplementation of fermented apple pomace (FAP) and cinnamon on laying performance, egg quality and blood characteristics in laying hens. A total of two hundred 57-wk-old Hy-Line laying hens were divided into five groups with 4 replicates of 10 birds each; control, 0.1% probiotics, 1.0% fermented apple pomace 1.0%, 0.1% cinnamon and 1.0% fermented apple pomace with 1.0% cinnamon. Chickens fed the diets containing 1.0% of fermented apple pomace showed higher egg production than the chickens fed the other diets. No synergic effect on laying performance was found when fermented apple pomace and cinnamon were added to the diets in laying hens. There was no significant major differences in egg quality and serum blood biochemical profiles. These results suggest the possibility that fermentation of apple pomace could be used as the alternative of antibiotic growth promoters.

• Korean Journal of Poultry Science
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• v.18 no.1
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• pp.33-42
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• 1991

In order to study effects of the 9round charcoal and organic acid on the egg production, White Leghorn strain(Hyline) layer of 113 week-old were fed control diet during a week of previous feeding and subsquent experimental diets during 12 weeks of experimental feeding . The experimental diets were the basal (control) diet composed of mainly corn-soybean meal, diet (CPB) substituted 0.5％ of ground charcoal with the defatted rice bran of the control, diet (PWV) added 0.1 mM(based on the acetic acid) of wood vinegar in the CPD and diet(PFA) added 0.1 mM (based on the acetic acid) of fermented acetic acid in the CPD. During experimental feeding period, birds (ed control, CPD and PWV diets showed similar feed intake which was shown a decreasing tendency in birds fed PFA diet as the passage of experimental feeding period. Birds fed experimental diets containing ground charcoal were tended to increase egg weight (g/egg) , while which of birds fed CPD was higher(P＜0.05) than that fed control diet. Chicks fed the control, CPD and PWV diets produced 75.9, 75.0 and 75. 9％ of egg, respectively, which were significantly(P＜0.05) higher than those of birds fed PFA. Daily egg mass(g/bird) were reached to 48.6, 49.9 and 49.5g i,1 layer fed the control, CPD and PWV diets, respectively, showing an increasing tendency in layer fed CPD and PWV compared with those of birds fed control, which were significantly (P＜0.05) higher than those of birds fed PFA . Although the effect of experimental diets on the feed efficiency (egg/feed) was not found, which was shown an increasing tendency in layer fed CPD compared with those in control diet. Compared with the incidence of cracked or shelless eggs in birds fed control diet, which were lowered to 37％ in birds fed CPD diet and 70％ in PWV-fed birds and increased to two times in birds fed PFA . The contents of cholesterol in egg was not affected by experimental diets, while birds fed CPD diet increased significantly(P＜0.05) the daily biosynthesis of egg protein and showed a trend to increase the thickness of eggshell and eggshell contents per eggs compared with that of control diet-fed birds. The results indicated that the ground charcoal powder improved the performance of layer.