• Journal of Sericultural and Entomological Science
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• v.50 no.1
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• pp.5-9
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• 2012

A new silkworm variety SooOkJam for spring rearing season is F1 hybrid between Jam157, a japanese race bred from introduction breeding and Jam158, a chinese race from introduction breeding. In the local adaptability test performed at 8 local areas in spring of 2011, the hatchability rate of SooOkJam was recorded 2% higher than the authorized silkworm variety, DaePoongJam. The larval period was recorded 12 hour shorter than DaePoongJam. The pupation percentage was recorded 0.8% higher than DaePoongJam. Single cocoon weight (2.40 g), Cocoon yield (22.6 kg) and best cocoon rate (95.5%) was similar to DaePoongJam. The concentration of DNJ was measured 4.12 mg in SooOkJam, lower than DaePoongJam (4.45 mg). Test of the artificial diet of SooOkJam showed excellent adaptability of the artificial diet for larval period from 1st to 3rd, similar to KumOkJam. In the Paecilomyces tenuipes production ability test, the pupal weight of SooOkJam was 1.61 g/individual, similar to DaePoongJam (1.65 g/individual).

• Journal of Sericultural and Entomological Science
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• v.49 no.1
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• pp.1-7
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• 2007

We investigated the selection and sensitivity to environmental mutagen of silkworm reared artificial diet to develop all-year-round operation system using a specific locus mutation of Bombyx mori. In the system, mutagenicity could be detected by the egg colour manifested by the pe and/or re genes, which is a kind of recessive visible mutation of the insect. Among, hi, Backokjam, C5, and N12, varieties of silkworm, AT was higher than other varieties in eclosion rate of female, and C5 and N12 were higher in fertility of male. Bakokjam was higher in eclosion rate of female, rate of moth to lay eggs normally in female and male, no. of eggs layed in female and fertility of female. As above results, Bakokjam was finally selected as the most fitness one among varieties of silkworm reared artificial diet. But the sensitivity to mutagen was lower than other varieties. In the sensitivity to mutagen, AT was the most sensitivity to mutagen in tested varieties of silkworm. To use AT variety in this system, AT was improved major characteristics, eclosion rate, fertility, rate of moth to lay eggs normally, and so on, by crossing of other varieties including Bakokjam.

• Korean Journal of Environment and Ecology
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• v.35 no.6
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• pp.601-608
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• 2021

This study surveyed the ecological characteristics of Squalidus multimacultus at Taehwa River tributary Cheokgwa Stream from January to December 2020. The species inhabited the riverbed that was mostly covered with sand. The water depth was 25-164 cm, and the average was rather deep at 68 cm. The stream velocity was slow at 0.21±0.26 (0.16-0.43) m/sec. The gender ratio of females to males was 1:0.99. The age according to the total length-frequency distribution indicated that the group with less than 50 mm (29.4 - 49 mm) in total length was one year old, the group with 50 - 69 mm was two years old, the group with 70 - 89 mm was three years old, and the group over 90 mm was four years old. The total length of sexually mature fishes was 40 mm for both males and females. The spawning season was from July to August, and the water temperatures was 23.8 - 25.4℃ during the period. The prosperous spawning season was August. The average number of eggs in the ovaries was 1,395 (648 - 2,201) per matured female, and the matured eggs were yellowish and spherical with a mean diameter of 0.67±0.24 (0.62 - 0.83) mm. The live foods were of S. multimacultus attached algae, zooplankton, aquatic insects, and Mollusca. The feeding habits of S. multimacultus were omnivorous, but more than 95% of the stomach content was plant-attached algae. The larger the size of this species, the greater the amount and frequency of eating aquatic insects, which were animal feeds. The population that ate aquatic insects did not eat vegetable food.

• Journal of Animal Science and Technology
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• v.44 no.1
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• pp.55-60
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• 2002

Two experiments were conducted to investigate the effect of dietary supplementation of plant phytase (Phytazyme$^{(R)}$) in corn-soybean meal based diets on utilization of phytase-bound phosphorus in laying hens and evaluate nitrogen(N) digestibility and phosphorus(P) availability in breeders. In the experiment one, three levels of the Phytazyme$^{(R)}$(0.05, 0.1, and 0.2% of diet) were added to diets containing a half of control TCP level(0.96%) for 4 wks. Feed consumption, egg production rate, egg weight and eggshell quality were recorded weekly. At the end of experiment, 8 birds per treatment were sacrificed, liver weight were weighed and right tibiae were removed for determination of P content. The second experiment was conducted to evaluate the P availability and nitrogen digestibility in breeders fed same diets for 2 wks. Feed and excreta were collected to determine the P and N contents for the last three days of experiment two. Addition of Phytazyme$^{(R)}$ resulted in no effects on feed intake, egg product rate, egg weight and egg shell quality. P excretion decreased and its availability enhanced as phytase supplementation increased in diets. Dietary supplementation of Phytazyme$^{(R)}$ above 0.1% level in corn-soybean meal based diets did not have an adverse effect on production and decreased level of phosphorus in excreta.

• 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 Ecology and Environment
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• v.33 no.3 s.91
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• pp.282-294
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• 2000

The reproductive ecology and the early life history of Macropodus chinensis were investigated in aquarium. Mature male made the bubble nest and spawned with wrapping the female and reverse posture. The parental male protected the offspring until the larvae depart the bubble nest. Egg productivity and egg hatching rate were the highest at water temperature in $28^{\circ}C$ and $26^{\circ}C$ respectivity than any other artificial temperature. The eggs were buoyant, globular and 0.95${\sim}$1.05 mm in diameter. Cleavage was progressed at intervals of 15 minutes. Eggs hatched in 42${\sim}$44hours after fertilization and the newly hatched larvae were 3.0${\sim}$3.2 mm in total length. The lawae were 4.5${\sim}$5.4 mm in 4${\sim}$5 days after hatching and fed on the food with dispersion from the nest. In 40${\sim}$45 days after hatching, all fin rays completely developed, and juveniles reached 18.2${\sim}$23.5 mm in total length. In 90${\sim}$110 days after hatching, body from of young fishes were similar to adult with 37.4${\sim}$48.2 mm and represented secondary sexual characters longer than 45.0 mm in total length, and about 120 days, fishes began spawning(water temperature for ontogenesis: $26.0{\pm} 1^{\circ}C$).

• KOREAN POULTRY JOURNAL
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• v.5 no.10 s.48
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• pp.57-72
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• 1973

1. 육추율, 육성율, 성계생존율 육추율은 99.9$\%$로서 1회 98.5$\%$, 2회 99.2$\%$, 3회 99.8$\%$, 4회 98.3$\%$, 5회 98.7$\%$, 6회 99.7$\%$와 비슷하였다. 육성율은 평균 98.8$\%$로서 1회 97.5$\%$, 2회 97.2$\%$, 3회 96.6$\%$, 4회 97.9$\%$와는 큰차가 없었고 5회 89.7$\%$ 6회 87.1$\%$ 보다는 약 12$\%$가 높게 나타났다. 이는 MD 백신접종 때문인 것으로 생각되며 성계생존율은 평균 86.3$\%$로서 87.3$\%$ 보다는 약 1$\%$낮았고 1회 80.3$\%$ 2회 84.8$\%$보다는 약 4.6$\%$ 높고 3회 71.8$\%$, 5회 71.4$\%$, 6회 75.3$\%$에 비하면 19$\%$나 높았다. 2. 성성숙일령 전체평균은 157.3일로 가장 빠른 구는 4구의 146일이고 가장 늦은 구는 10구와 17구의 161일이였다. 3. 산란율, 산란지수 산란율은 평균 62.0$\%$이고 가장 높은 구는 15구의 68.9$\%$ 이였다. 산란지수는 평균 205.1개로 1회 190.8, 2회 198.3, 3회 184.2, 5회 186.5, 6회 189.7개에 비하여 높고 4회때와 근사하였다. 4. 사료요구율 전체평균 3.23으로 1회 3.54, 2회 3.1과는 근사하나 3회 2.98, 4회 2.87 5회 2.83에 비하여 낮은 것은 사양표준은 작년도와 같으나 원료사료 특히 단백질 사료의 품질저하에 원인이 있었다. 5. 난평균 중량 검정계군 전체의 평균난중은 61.2g으로 최상위구는 64.70g, 최하위구는 58.3g이였다. 6. 체중 검정계의 전체의 평균제중은 300일령 1925.1g, 500일 1938.4g이며 유색품종은 300일령 1986.7g, 500일령 1948.4g이였다. 7. 사료섭취량 사료섭취량 평균은 1일수당 육추기 32.1g 육성기 73.0g 산란기 115.6g이었다. 8. 경제성 총 수입은 7,269,072.34으로 전체수입의 85$\%$가 계란수입이고 15$\%$는 폐계수입이었다. 지출은 5049,690으로 전체 지출의 99.95$\%$가 사료비 0.05$\%$가 초생추대이었다. 9. 후기 검정수수미달은 참고구로 처리하였고 축산시험장과 대천종축장에서는 당초부터 참고구로 출품하였다. 대신의 개리슨, 신기의 하바드 코메트는 수정율이 낮아서 검정수수가 미달되었으며 영국의 Sykes International Co. 에서 출품한 Sykes Tinted(WL$\times$RIR BX)는 출품회사에서 직접 종란을 항공편에 보내 인수 부화하여 검정하였다. 7회 부터는 초생추에 MD(뎁타백) 백신을 하여 초산전후에 폐사율이 적었으며 72년 11월부터 국산어분에 의한 염도의 과다에 의하여 약 2주일 설사를 하여 상당히 스트레스를 받은 바 있었다.

• Korean Journal of Ichthyology
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• v.12 no.2
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• pp.101-110
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• 2000

Population ecology of Rhynchocypris keumgangensis have been investigated at upper part of the Han River in Korea from January to December, 1995. The habitat was low water temperature and clean area, and stream form was Aa. The major cohabitation fish was Phoxinus phoxinus. The total lengths in this population indicated that below 40 mm group is one year old, 40~65 mm group is two years old, 65~80 mm group is three year and the 80 mm longer group is regarded over four years old. There were no differences in total length distribution between the female and the male. The males became sexually mature, when longer than 45 mm and females longer than 65 mm in total length. Spawning season was from April to mid May with the water temperature in $11{\sim}14^{\circ}C$ and the properous period was April. The mean number of eggs in ovary was 1,616. The sex ratio all the year round of the female to the male was 1 : 0.75. The current velocity of the spawning ground was 44 (20~80) cm/sec and water depth was 35 (5~70) cm. Eggs were laied in 5~15 cm deep underneath the immaculate pebbles (2~6 cm). Sex ratio of the female to the male was 1 : 6.90 for spawning behavior.

• Korean journal of applied entomology
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• v.44 no.4 s.141
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• pp.257-264
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• 2005

In order to establish the successive rearing system brush-footed butterflies (Lepidoptera : Nymphalidae) were reared in a room. Artificial diets were developed for a year-round rearing. Bu-diet was best to rear these butterflies among 3 kinds of diet used. The freeze-dried host plant leaf powder in diet was better than heat-dried one $(60^{\circ}C)$ in the growth of larvae. The rearing results were best in the diet C/N ratio was 1:1. The 24-hrs old eggs could be stored for 5 days at $15^{\circ}C$ or for 3 days at $5^{\circ}C$ and showed 75% of hatchability. On the other hand, pupae could be stored for maximum 15 days at $15^{\circ}C$ because the emergence of abnormal adults appeared much more as the cold storage period got longer. And the adult was able to be stored until 60 days at refrigerator without relation of nectar-sucking period before cold-storage and storage temperature. Also a simple artificial ovipositing kit was devised by ${\Phi}9$ cm of petri-dish and a female oviposited $278{\pm}27$ of eggs with adding the ether extract of host plant to this kit. The systematic successive rearing method of brush-footed butterflies in a room was completed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.9 no.1
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• pp.61-68
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• 1976

For the artificial precocious breeding of abalone effects of changes in environmental parameters, water temperature and light period, on the induction of spawning have been studied. Subtidal specimens of Haliotis discus hannai were collected irregularly for 6 times from April to June 1975 in Chungmu Bay near Jukdo Island, the southern coast of Korea. One hundred and fifty specimens were reared in 4 aquarium tanks in the laboratory and in a creel submerged in the sea during the period of 60 days from April 24 to June 23, 1975. The all groups kept in the four tanks and a creel showed very high spawning rates $(70\~100\%)$, compared to those inhabited the natural environment at sea until right before the spawning time $(0\~50\%,\;average\;16.4\%)$. From the results of the present induced spawning, the parameters can be discussed as follows: It seems likely that photoenvironment may stimulate to produce and secrete some internal substances which may concern to giving the fertilizing ability to the eggs before spawning and to inducing spawning, but the temperature may not be a factor for this concern. For effective precocious breeding, it seems to require that abalones are to be realoed under controlled conditions of darkness below 2,000 lux even during day time for more than 60 days before inducing spawning.