• Korean Journal of Poultry Science
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• v.7 no.1
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• pp.43-51
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• 1980

This study was carried out to investigate reasonable Period of egg production for incubation and to survey the change of sex ratio with the age as the preliminary work to make breed which can produce progeny in controlled sex ratio. The analyzed data was obtained from the record of incubations during 165-262 hys of age in White Leghorn. The results can be summarized as follows: 1. It was appeared that the fertility and hatchability were increased with the egg produced over 7 months of age. 2. It was tendency that the fertility and hatchability of the flock produced a more female chicken (40% flock) were higher than those of flock produced a more male chicken (60% flock). 3. The variation of sex ratio with the age was wider in 60% flock than in 40% flock 4. 60% flock showed heavier egg weight and body weight, in a while, 40% flock better sexual maturity and hen- housed egg production. 5. There was a negative correlation between sex ratio and henhoused egg production in 60% flock, but 40% flock appeared a positive correlation.

• Korean Journal of Poultry Science
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• v.39 no.4
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• pp.283-290
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• 2012

The objective of this study was to compare the growth performance between Korean native layer chickens and imported layer chickens at early rearing stage. Total number of chicks analyzed in this study was 276 and feeding period was conducted from July 24, 2012 for 10 weeks. Five strains including 2 Korean native strains: A=Korean Native Black (Chungcheongbuk-do) and B=Korean Native Yellowish Brown (Gyeongsangbuk-do) and 3 imported layer strains: C=White Leghorn (Gyeongsangnam-do), D=White Leghorn (Seoul), and E=Ameraucanas (Gyeongsangbuk-do) were used to analyze the following traits such as fertility, hatchability, body weight at a different growing stage, average body weight gain, and feed conversion ratio. The fertilities and hatchabilities of strains were 93.88% and 95.65% in strain A, 81.75% and 86.24% in strain B, 82.25% and 88.15% in strain C, 79.25% and 90.85% in strain D, and 71.50% and 88.11% in strain E, respectively. A viability was excellent in strains A and E to be more than 98% and was low in strain D to be 86.67% at a whole week. The strain A had greater body weight during growing stages (p<0.05) than the other strains. The shank length of strain D of $56.69{\pm}3.27mm$ was the highest value at 10 weeks of age among strains (p<0.05). The phenotypic correlation coefficients of strains A and D between an average body weight gain and a shank length were 0.63 and 0.73 during 0~2 wk, 0.70 and 0.55 during 2~4 wk, 0.55 and 0.54 during 4~6 wk, 0.50 and 0.24 during 6~8 wk, and 0.46 and 0.29 during 8~10 wk, respectively. The Korean native hens may have potential abilities to be used as an excellent seed stock for poultry industry.

• Korean journal of applied entomology
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• v.51 no.4
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• pp.485-488
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• 2012

The life table of the Striped Fruit Fly, Bactrocera scutellata, was analyzed by using adult longevity and fecundity of B. scutellata at seven constant temperatures (15, 18, 21, 24, 27, 30, $33{\pm}1.0^{\circ}C$) with 65% RH and 16L:8D in the laboratory. The highest values of longevity were observed at $21^{\circ}C$ with the values of 138.0 days for male and 131.2 days for female, respectively. Females of B. scutellata did not oviposit under $18^{\circ}C$ and larvae of B. scutellata could not survive to adulthood over $33^{\circ}C$. The highest value of total fecundity was observed at $24^{\circ}C$ (111.4 eggs) and daily fecundity per female was observed at approximately 1.0. The parameters of the life table were calculated by using the data from eggs to adults of B. scutellata at 4 different temperatures. Net reproduction rate ($R_o$) was highest at $21^{\circ}C$ (52.27). The intrinsic rate of increase ($r_m$) and the finite rate of increase per day (${\lambda}$) were highest at $27^{\circ}C$ (0.07 and 1.07), respectively. The doubling time ($D_t$) was shortest at $27^{\circ}C$ (with 10.02). The mean generation time (T) was shortest at $27^{\circ}C$(50.39).

• Food Science of Animal Resources
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• v.30 no.3
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• pp.449-457
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• 2010

This study investigated the effects of three kinds of water extract mixtures each with different ratios of A. capillaris, C. sinensis, S. chinensis, and V. coloratum on laying performance, egg quality, blood characteristics, and egg storage stability in laying hens. One hundred and sixty 35-wk-old laying hens (Hy-line brown) were divided into four groups of 10 birds each replicated times four. The treatments involved a basal diet (C, control) or diets containing three kinds of water extract mixtures at 200 ppm (T1, water extract mixture A; T2, water extract mixture B; T3, water extract mixture C). The egg production rate, egg mass, and feed conversion ratio were significantly improved in all treatments compared to those of control (p<0.05). Haugh unit and egg yolk color in all treated groups were significantly improved in comparison with control (p<0.05), but no significant differences were observed for egg shell quality. The content of total cholesterol in blood serum was significantly decreased in all treatments compared to that of control (p<0.05). The blood biochemical parameters of liver and kidney damage were significantly decreased in all treatments compared to those of control (p<0.05). Total antioxidant activity in the blood serum of all treated groups was increased as well. The Haugh unit and malondialdehyde content in the egg yolk during storage were significantly decreased in all treated groups compared to control (p<0.05). Consequently, the dietary supplementation of water extract mixtures of A. capillaris, C. sinensis, S. chinensis, and V. coloratum improved laying performance and egg quality but decreased egg quality deterioration with increased storage. These results suggest that medicinal plant extracts could be used as a feed additive in feed for laying hens.

• Korean journal of applied entomology
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• v.61 no.2
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• pp.377-385
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• 2022

Most pruning branches of mulberry, Korean raspberry (bokbunja), and blueberries are discarded without use. These discarded pruning branches were utilized as feed in the investigation of the development and oviposition characteristics of Protaetia brevitarsis with a focus on breeding possibilities. It was observed that the developmental period of P. brevitarsis larvae fed with berry fermented sawdust from mulberry, bokbunja, and blueberry was shortened to 157.3 130.3 days, and 140 days, respectively, compared to 169.3 days for those fed with oak fermented sawdust. The weight and survival rate of the larvae also increased. Under all three types of fermented sawdust feed, the percentage of larvae with weight ≧ 2.5 g during the group was over 60% between 6-8 weeks after hatching; however under oak fermented sawdust feed, it was within 10%, and the percentage only increased after 10 weeks. The average number of eggs laid per female was ≧ 80, with an average oviposition period of approximately 9 weeks; however, there was no significant difference owing to the large deviation per individual. Furthermore, mixed fermented sawdust from the three berries enhanced the growth rate of larvae, and there was no difference in the number of eggs laid compared to those fed with control oak fermented sawdust. Our study demonstrates berry fermentation sawdust is just as effective as oak fermentation sawdust in the breeding of P. brevitarsis.

• Korean Journal of Poultry Science
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• v.50 no.4
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• pp.203-212
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• 2023

This study conducted a diallel-crossbreeding test using four Korean native chicken parent stock lines (YC, YD, CK, and CF) to develop a native commercial layer with high egg-laying performance. A total of 312 chickens in six combinations were examined for various traits, including livability, body weight, age at first egg-laying, hen-day, and hen-housed egg production, egg weight, and egg quality, from hatching to 60 weeks of age. The results showed that the average survival rate was 77.1±18.8% with the YDYC combination having the highest survival rate along with excellent specific combining ability. The YDYC combination exhibited significantly higher body weight compared to the other combinations (P<0.01). The average age at first egg-laying was 121.3±2.5 days, with no significant difference between the combinations. The average hen-day egg production was 74.0±6.4%, and the hen-housed egg production was 181.4±33.8 eggs with the YDCF and YCCK combinations demonstrating the highest laying performance, while the YDYC and CKCF combinations had the lowest (P<0.05). Laying performance was more influenced by specific combining ability than general combining ability. The eggs from the YDYC combination were significantly lighter and had the darkest shell color (P<0.01), whereas the YDCF combination exhibited the thickest eggshells. There was no difference in internal egg quality among combinations, except the YDCF combination had the darkest yolk color. Overall, we concluded that the YCCK combination, characterized by high laying performance and livability, and the YDCF combination with high laying performance and good egg quality are the most desirable combinations for Korean native commercial layers.

• Journal of Sericultural and Entomological Science
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• v.55 no.1
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• pp.1-5
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• 2019

This study was carried out to investigate the development and oviposition characteristics of Tenodera aridifolia. The nymphs of T. aridifolia grew to adults through 6 and 7 nymphal instars. The percentage of 7 nymphal instars (7-instar type) at 25, 28, and $30^{\circ}C$ were 77.3, 76.2, and 73.5%, respectively. In the 7 instars type, total nymphal periods at 25, 28, and $30^{\circ}C$ were 71.9, 53.5, and 54.7 days, respectively. And, there was no difference in deveolpmental periods between 6- and 7-instar types at all temperatures. Egg periods were 41.3 days at $25^{\circ}C$. Adult longevity of females were 82.0 days, deposited average 3.2 oothecae at intervals of 11.7~18.7 days at $28^{\circ}C$ during her life span. The first ootheca was the largest and $40.5mm{\times}22.0mm{\times}17.3mm$ in size. The number of average eggs per oothecae was 178.6 at $28^{\circ}C$.

• Korean journal of applied entomology
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• v.52 no.4
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• pp.283-289
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• 2013

This study was performed to investigate the biological characteristics of the brown lacewing Micromus angulatus (Stephens) at four different temperatures (15, 20, 25, and $30^{\circ}C$) and $70{\pm}10%$ relative humidity under a photoperiodic regime of 16:8(L:D) h. The developmental threshold and effective accumulative temperature from egg to pupa for M. angulatus were $9.6^{\circ}C$ and 270.3 day-degrees, respectively. The developmental period of egg, larva, and pupa at $25^{\circ}C$ was 4.4, 5.5, and 6.9 days. respectively. The longevity of an adult female M. angulatus was 34.9 days. The oviposition period for M. angulatus was 28.7 days, in which it laid a total number of 515.2 eggs during its life span. The maximum number of eggs laid by a female in a day was 54.8. Daily consumption by M. angulatus at $25^{\circ}C$ was 18.9 $1^{st}$ instars, 47.2 $2^{nd}$ instars, 57.7 $3^{rd}$ instars, and 91.0 adults of the glasshouse potato aphid, Aulacorthum solani. Therefore, M. angulatus could be a promising biological control agent against aphids.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.4
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• pp.105-111
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• 2004

When the clitellate tiger worms(Eisenia fetida) were fed with paper mill sludge, sewage sludge of agricultural-urban area and sewage sludge of agricultural area, number of cocoons produced by individual clitellate earthworm for 104 days were 11.8, 8.6 and 3.5, respectively. However, clitellate earthworms that had been fed with sewage sludge of agricultural-urban area for 52 days or fed with sewage sludge of agricultural area for 95 days could not produce cocoons, whereas the earthworms that were fed with paper mill sludge kept producing cocoons through the investigating period. The hatchability of cocoons produced by the clitellate tiger worms(Eisenia fetida) fed with sewage sludge of agricultural-urban region, sewage sludge of agricultural region and paper mill sludge were 42.8%, 38.3% and 39.2%, respectively. And hatching periods of cocoons were 33.8~36.0 days, which were not affected by the kinds of sludges. However, the cocoons produced by clitellate earthworms which had been fed with sewage sludge for about 1.5 months could not hatch at all. Death rates of second generation hatched from cocoons produced by tiger worms(Eisenia fetida) which had been fed with the sewage sludge from agricultural-urban region and the sewage sludge from agricultural region reached to 100% and 90% at 60 days after hatching, respectively, whereas death rate of second generation fed with paper mill sludge reached to 16%.

• Korean Journal of Poultry Science
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• v.34 no.3
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• pp.181-185
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• 2007

This study was conducted to evaluate the effects of dietary delta-aminolevulinic acid (ALA) on egg production and egg quality in laying hens. A total of 114 (30-wk age) ISA brown commercial hens were used in current trial for 28 days. Dietary treatments included 1) CON (basal diet), 2) 0.05 (basal diet + ALA 0.05%), 3) 0.1 (basal diet + ALA 0.1%) and 4) 0.2 (basal diet + ALA 0.2%). There were four dietary treatments with four replication per treatment and twelve laying hens per replication. During the overall period, egg production was quadratically affected (P=0.01) by ALA supplementation compared with control treatment. Egg weight increased (linear effect, P=0.01; quadratic effect, P=0.01) as the level of delta-aminolevulinic acid supplementation increased in the diets. Yolk color was increased quadratically (P=0.03). The difference of hemoglobin concentration was increased (quadratic effect, P=0.01) as the level of delta-aminolevulinic acid supplementation increased in the diets. In conclusion, the results of the experiment suggest that dietary delta-aminolevulinic acid could affect egg weight, yolk color and hemoglobin concentration in laying hens.