• Journal of Animal Science and Technology
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• v.52 no.5
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• pp.389-398
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• 2010

The objective of this study was to investigate the effects of three strains of Bacillus subtilis (B. subtilis) supplemented to diets on egg production, egg quality, egg yolk cholesterol levels, the profile of cecal microflora, and tibia characteristics in laying hens. One hundred sixty 76-week-old Hy-Line Brown layers were randomly divided into 4 groups with 4 replicates per group (10 birds per replicate). Birds in the control group were fed a corn-soybean meal based diet. The remaining three treated groups were fed the control diet containing either 0.05% B. subtilis Ch3 (T1), 0.05% B. subtilis Ch3 + B. subtilis W1 (T2) or 0.05% B. subtilis commercial product (T3) for 6 weeks, respectively. There were no differences in feed intake, egg weight, egg production and egg mass among the groups. The dietary supplementation of B. subtilis improved eggshell strength and Haugh units compared to those of control (P<0.05). The activities of GOT and GPT in serum were not also affected by the dietary treatments. The population of total microbes and lactic acid bacteria in cecum were significantly increased by the dietary B. subtilis (P<0.05), but not the coliforms. The cholesterol concentration in egg yolk and serum in the treated groups were significantly decreased compared to those of control (P<0.05). Also, The levels of phospholipids in serum were significantly decreased compared to those of control (P<0.05). The supplementation of three strains of B. subtilis to diets significantly increased the contents of tibia ash compared to that of control (P<0.05). Thus, this study showed significant improvements in egg quality, such as eggshell strength and Haugh unit, by dietary B. subtilis strains. The B. subtilis strains added to the diets modulated the profiles of cecal microflora, reflecting beneficial effects in laying hens.

• Journal of Life Science
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• v.18 no.12
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• pp.1728-1732
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• 2008

This study was performed to investigate the bionomical characteristics of Luciola lateralis in Korea. Imago's longevity of female was $17.5{\pm}0.7$ and male was $20.6{\pm}1.0$ days at $23^{\circ}C$, R.H. 80%, and significant difference was not occurred in breeding density. Pre-oviposition period was a pair $2.8{\pm}1.5$, two pairs $2.5{\pm}1.5$, three pairs $1.7{\pm}0.7$, four pairs $1.3{\pm}0.5$ days and pre-oviposition period was shorten in higher breeding density. The mean of laying eggs was $248.9{\pm}80.7$, was not related breeding density. Daily oviposition rate was 1st day 20.8%, 2nd 17.3%, 3rd 14.3%, 4th 12.7%, 5th 7.0%, the rate was highest in 1st day and gradually reduced. Egg period was $21.8{\pm}0.7$ days and hatchability was $95.5{\pm}4.8%$. Larval instar was identified the 9th instar, the evidence was able to its skin and marking pattern. Larval period of each instar was 1st $1.0{\pm}0.1$, 2nd $3.3{\pm}0.2$, 3rd $10.2{\pm}1.0$, 4th $6.8{\pm}0.5$, 5th $6.9{\pm}2.0$, 6th $15.4{\pm}4.1$, 7th $18.3{\pm}5.9$, 8th $25.8{\pm}8.7$, 9th $31.2{\pm}13.2$ days. Matured 9th larva was made of cocoon during $2.8{\pm}0.8$ days and pre-pupal, pupal period was $4.6{\pm}0.9$, $5.6{\pm}0.7$ days. Imago was made hard hind wing during $3.8{\pm}0.4$ days in cocoon and come out.

• Korean Journal of Poultry Science
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• v.37 no.1
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• pp.51-62
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• 2010

This study was conducted to investigate the effects of dietary supplementation of multiple probiotics on the performance, small intestinal microflora and immune response in laying hens and broilers. In Exp.1, a total of 800, 82 wk old Hy-line Brown$^{(R)}$ laying hens were assigned to one of the following five dietary treatment; Control, Antibiotics (avilamycin 6 ppm), Probiotics; PB-M (Micro-ferm$^{(R)}$ 0.2%), PB-L (Lacto-sacc$^{(R)}$ 0.1%), PB-Y (Y University probiotics 0.2%). Each treatment was replicated eight times with 20 birds in each replicate and two birds were housed in each cage. Twenty birds units were arranged according to completely randomized block design. Feeding trial lasted 6 wk under 16 h lighting regimen. The Exp. 2, was conducted with a total of 1,000 broilers chicks (Ross$^{(R)}$). They were divided into five treatments, same as those of Exp. 1. Birds were fed starter (0~3 wk) and grower (4~5 wk) diets. Each treatment was replicated four times with 50 birds per pen comprising of deep litter. In Exp. 1, egg production parameters, such as hen-day and hen-house egg production, egg weight, broken and soft shell egg production, feed intake and feed conversion were not significantly different among treatments. However, strength and thickness of eggshell were significantly (P<0.05) different. Among the probiotics, PB-Y showed the highest strength and thickness of eggshell. Eggshell color, egg yolk color and Haugh unit were not significantly influenced. In Exp. 2, overall weight gain (0~5 wk) and mortality were not significantly different among treatments. However, weight gain of birds from PB-Y treatment during starter (0~3 wk) was significantly lower than the birds from Control and Antibiotic treatment. During the whole period (0~5 wk), birds from Antibiotics treatment had higher feed intake and Production Index (PI) and lower feed conversion than birds from Control treatment. Probiotics treatments were not significantly different from the Control on feed intake and feed conversion. In Exp.1, there were significant (P<0.05) differences in leukocytes parameters, such as white blood cell (WBC), hetrophil (HE), lymphocytes (LY), monocyte (MO), eosinophil (EO) and stress index (SI; HE/LY) in the blood of layers. Birds from Antibiotics and probiotics treatments tended to increase these parameters. In Exp. 2, however, only SI was significantly (P<0.05) decreased in Antibiotics treatments. Concentration of serum immunoglobulin (IgG) were higher (P<0.05) in PB-M and PB-Y treatments when compared with Control treatment in Exp. 1. The population of E. coli significantly (P<0.05) decreased in birds from Antibiotics, PB-L and PB-Y treatments when compared with birds from Control treatment in Exp. 1. Metalbolizability of crude fat decreased significantly (P<0.05) in birds from probiotic treatments in Exp. 2. It was concluded that the response of probiotics on the productivity of layers and broilers were different. Probiotics increased strength and thickness of eggshell in layers, and decreased feed conversion and increased PI in broilers. Leukocytes and IgG tended to increase by supplementation of antibiotics and probiotics in layers. Intestinal E. coli tended to decrease in layers. Digestibility of crude fat of diet decreased in probiotics treatments broilers. Parameters of blood and microbial were more sensitive in layers than broilers.

• Korean Journal of Poultry Science
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• v.35 no.2
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• pp.143-151
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• 2008

This study was conducted to identify the correlation of bacterial phytase ($Transphos^{(R)}$) to the calcium level in feed. Of all 21-week-old 720 HyLine brown laying hens, 2 birds of similar weight were placed on each individual cage. The experiment was conducted by $3{\times}2{\times}3$ factorial design with including 3 different levels of phytase (0, 300, and 1,000 DPU/kg), 2 different levels of calcium (3.5% and 4.0%), and 3 different levels of no NPP addition 0% (0.095 NPP), 0.5% (0.185% NPP), and 1.0% (0.275% NPP). The feeding trial maintained the ME level of 2,800 kcal/kg and 16% for crude protein. The diet was fed ad libitum and 17 hours of lighting was provided throughout the experimental period. Egg production seemed to increase, in the 300 DPU of bacterial phytase added group and the cracked egg tended to reduce in Transphos added group. The egg productivity between treatment groups did not show significant difference by dietary calcium level, whereas non NPP added group (0.095% NPP) was found to be low compared to NPP added groups (P<0.05). The highest mean egg weight and the highest daily egg mass were detected in 300 DPU phytase added group. Although the mean egg weight was significantly higher in treatment groups fed with 3.5% calcium containing feeds (P<0.05), daily egg mass was no among treatment groups. The mean egg weight and daily egg mass were the lowest in non NPP added group (0.095% NPP) compared to other treatment groups (P<0.05). The feed intake showed similar pattern regardless of the bacterial phytase and calcium levels in the diet. However, the treatment groups fed diets containing NPP level of 0.275% and 0.165% showed significantly higher feed intake than the group fed with 0.095% NPP (P<0.05). Although the feed conversion was not affected by calcium and NPP levels in the diet, the most improved result was obtained from 300 DPU phytase added group (P<0.05). The eggshell breaking strength and thickness increased as dietary calcium level increase the level of calcium increases in diet. The treatment groups fed diet containing 0.275% and 0.165% NPP revealed to show improvement in eggshell breaking strength and yolk color index compared to the NPP non added (0.095% NPP) treatment group. The result of the present study suggests that the appropriate level of microbial phytase is 300 DPU and at this level, tricalciumphosphate supplementation in feed can be reduced to 40% of NRC recommendation. Higher calcium level in feed fail to show synergistic effect by adding microbial phytase.

• Korean journal of applied entomology
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• v.42 no.3
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• pp.241-248
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• 2003

The aphid-eating gall-midge, Aphidoletes aphidimyza (Rondani), as predator of aphids was wildly used as one of the biological control agents for control of several kinds of aphids. Their some kinds of biological characteristics were examined. The developmental periods of A. aphidimyza from egg to adult with the green peach aphid as prey were 40 and 12 days at 15$^{\circ}C$ and 30$^{\circ}C$, respectively. Supplying the cotton aphid as prey, their developmental periods were shorter than with the green peach aphid. In case of the preservation of pupa in the cold condition, emergence rates were over 90% for 1 and 2 weeks at 5$^{\circ}C$ and l0$^{\circ}C$, respectively. Adult females of A. aphidimyza began mating and laying eggs at 2-3 days after emergence, and they laid about 200 eggs for lo days of average life span. Most of adults were emerged from pupa at 6 to 8 pm during a day, and they mainly acted in the early night.

• Korean journal of applied entomology
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• v.40 no.1
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• pp.41-43
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• 2001

Persimmon fruit moth, Stathmopoda masinissa, collected from roadside persimmon trees planted as shade trees in yeongdong area was used to investigate their developmental ecology under laboratory conditions; $25\pm$ $1^{\circ}C$, 16L : 8D and 85% RH. Developmental periods for eggs, larvae, and pupae were 7.4, 34.8 and 15.5 days, respectively. The duration for each larval instar from the 1st to the 5th was 3.5, 4.2, 5.2, 6.5 and 15.4 days, respectively, and the head capsule width of corresponding stage was 0.20, 0.40, 0.65, 0.87 and 1.07 mm. Rates of pupation and emergence were 68.0 and 59.9%, respectively. Longevity of adult males was 6.2 days while that of females was 10.1 days. Average fecundity was 25.4 eggs.

• Korean journal of applied entomology
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• v.41 no.2
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• pp.85-89
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• 2002

Development and reproduction of the rice armyworm, Pseudaletia separara, were investigated on different diets (corn leaf, rice leaf, Chinese cabbage leaf, cabbage leaf, sweetpotato leaf, soybean leaf and silkworm artificial diet). Egg and pupal periods were not different among the diets. But larval periods showed significant difference among diets. Developmental period from egg to adult was shortest as 32.5 d on corn leaf and longest as 46.6 d on soybean leaf. At 16 days after hatching, larval weights on rice and silkworm artificial diet were heavier than those on other diets. The larvae reared on cabbage leaf and sweetpotato leaf failed to pupate. Survival rates from larva to adult were highest (70.6%) on com leaf lowest (39.8%) on soybean leaf. The longevity of female adults was not affected by the larval diets. Female adults showed higher fecundity when the larvae were fed with corn leaf, rice leaf and silkworm artificial diet than other diets. Net reproduction rate (R$_{0}$) was highest as 1218.5 on silkworm artificial diet. The intrinsic rate of natural increase (R$_{0}$) ranged from 0.115 to 0.175, and was maximum on com leaf.

• Korean Journal of Ichthyology
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• v.35 no.4
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• pp.294-304
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• 2023

Seasonal variations in the community structure of larval fish assemblage in the coastal waters off Gadeok-do were investigated in May, August and November of 2019, and February in 2020. During the study period, a total of 85 larvae species belonging to 45 families were collected. The dominant species were Engraulis japonica, Gobiidae sp., Clupea pallasii, Decapterus maruadsi, and Callionymidae sp.. These five species accounted for 84.1% of the total number of larvae during the survey period. E. japonica, Gobiidae sp., D. maruadsi, and Callionymidae sp. were the dominant species in the summer, while C. pallasii was the dominant species in the winter. The Species Diversity Index was highest in the summer and lower in the fall and winter months, with the lowest values in the spring. As a result of cluster analysis using the number of individual larval fish showed that they are divided into four seasonal groups. In particular, due to seasonal changes in water temperature, an appropriate growth environment was formed in the summer, and an appropriate hatching water temperature for winter spawning fish species was formed in winter, reflecting the seasonal characteristics of the larval fish community.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.2 no.1
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• pp.41-46
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• 1969

산란기 직전의 참굴(Crussostrea gigas)을 통상 방법으로 개각하여 0.3 및 2.0 Mrad의 감마선에 각기 쬔 후 $0^{\circ}C$의 온도하에 저장기간중 번식하는 총 세균수와 pH 변화를 측정하고 부패상을 관찰함으로씨 방사선을 쬔 참굴의 저장성을 조사하였다. 자외선을 쬔 무균해수에 개각하지 않고 정화시킨 굴과 보통 해수에 수용하였던 굴을 비교하여 정화 처리에 의한 세균 제거의 효율을 조사하였으나 4-5일의 장기간 처리에도 불구하고 별다른 세균제거 결과를 볼 수 없었다. 이것은 굴이 보유하고 있는 본래의 총 세균수가 적기 때문이라고 추측된다. 감마선을 쬐지 않은 굴은 저장 15일째에 부패했음이 완연했으나 0.3 Mrad의 감마선을 쬔 굴은 35일후 까지도 시큼할뿐 별로 변질되지 않았다. 2.0 Mrad의 감마선을 쪼인 굴은 관능상의 선도 유지에 있어서 0.3 Mrad로 쬔 굴보다 휠씬 나빴고 off-odor가 심했다. 굴 저장중의 pH 변화로 선도를 판정함은 그 신빙성이 극히 희박하였고 선도의 저하와 함께 pH가 내려간다는 일반적인 인식과는 달리 어류부패의 경우와 같이 저장 초기에는 약간 하강하나 부패의 진행과 함께 상승함이 확인되었다.

• Journal of Sericultural and Entomological Science
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• v.36 no.1
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• pp.26-29
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• 1994

The topical application of methoprene a kind of juvenile hormone(JH) on 4th instar larvae at 48th hour after ecdysis-3 , followed by insulin on 5th instar larvae and silkgland weights, cocoon weight and cocoon shell weight, and fecundity ; and significantly decreases percent of cocooning and moth emergence. After treatment with methoprene followed by insulin, cocoon weight increase by 17~20% and cocoon shell weights by 18~32% respectively.