• 한국패류학회지
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• 제32권2호
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• pp.133-139
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• 2016

The incubation time required for hatching of O. ocellatus were investigated through the processes of egg and embryonic developments by the dissecting microscopic and visual observations. And differences in ecological characteristics of the plankton mode of life or the benthic mode of life according to total numbers of the suckers on each short arm of the hatched juvenile larvae of O. ocellatus were studied by comparisons with other octopodidae species. Compared with the recent a few results reported by other researchers associated with the incubation time required for hatching by female adult mother of O. minor (73-90 days after spawning at $20.9-21.5^{\circ}C$ ranges), in this study, the incubation time required for hatching by female adult mother of O. ocellatus was 56-57 days after spawning at $11.0-20.4^{\circ}C$. Therefore, the incubation time required for hatching by female adult mother varied with Octopodidae species. In this studies, each ovarian egg laid by a female was connected to an egg string attaching to the surface of the wall or bottom of vacunt shell of Rapana venosa. Egg and embryonic developments of this species were studied in the indoor aquaria, in the specific gravity ranging 1.024-1.025. the hatched juvenile of O. ocellatus is 10.3 mm in the mean total length and 4.5 mm in mantle length, and each of its short arms has 18-20 suckers. The just hatched juvenile larvae of O. ocellatus enter the benthic mode of life (benthic larval stage) after hatching. In particular, regarding differences in ecological characteristics of the mode of life according to total numbers of the suckers, O. vulgaris may not need to have many suckers because they enter the planktonic mode of life after hatching, however O. ocellatus may need to have many suckers, because they should adapt to the benthic mode of life. And also the just hatched juvenile larvae of O. minor (bearing many suckers more than O. ocellatus) enter the benthic mode of life (benthic larval stage) after hatching. Therefore, the total number of the suckers on each short arm of the hatched juvenile larvae can be used for determining whether an octopus species has planktonic larval stages or benthic larval stage (benthic mode of life). In particular, The intracohort cannibalism phenomena appeared at the hatched juvenile larval stage because the larval stage of O. ocellatus and O. minor enter into the benthic larval stage in the early stage, unlike entering into the plaktonic larval stage in other Octopus species such as O. vulgaris: at this time, the early hatched larvae fed the late hatched larvae (they are the same species and almost same ages). Therefore, the intracohort cannibalism pheneomena occur in the just hatched juvenile stage of only O. ocellatus and O. minor.

• 한국가금학회지
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• 제46권2호
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• pp.77-86
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• 2019

본 연구는 겨울철에 발생하여 육성된 닭들과 여름철에 발생하여 육성된 닭들 간의 열 스트레스 반응 정도와 생산능력을 비교 분석하고자 하였다. 공시계로는 겨울철에 발생된 한국토종종계 초생추 1,156수와 여름철에 발생된 초생추 934수로 총 2,090수를 분석 대상으로 하였다. 스트레스 반응정도와 생산능력을 비교하기 위하여 텔로미어의 함량과 heat shock proteins(HSPs)의 유전자 발현율을 분석하고, 생존율, 산란율 및 체중을 조사하였다. 분석 결과, HSP-70, $HSP-90{\alpha}$ 및 $HSP-90{\beta}$ 유전자 발현율은 겨울철에 발생하여 육성된 닭들이 여름철에 발생하여 육성된 닭들에 비하여 모두 유의하게 높은 발현값을 나타내었다. 텔로미어 함량은 겨울철과 여름철에 발생한 닭들 간에 유의한 차이가 없었다. 생존율에서는 여름철 발생하여 육성된 닭들이 겨울철에 발생하여 육성된 닭들에 비해 유의하게 높았고, 산란율 및 난중 또한 여름철 발생 계군이 높게 나타났다. 반면, 초산일령은 겨울철 발생 계군이 여름철 발생 계군에 비해 빨랐다. 체중에 있어서 24주까지는 겨울철 발생 계군이 여름철 발생 계군에 비해 높았으나, 28주 이후부터 발생 계군 간 역전된 결과를 보였다. 결론적으로 여름철에 발생하여 육성된 닭들이 겨울철에 발생하여 육성된 닭들에 비해 열 스트레스에 대한 저항성이 높고 생산성이 우수함을 보였다. 이는 발생 및 육성 초기에 고온에 노출된 닭들이 상대적으로 높은 열적응성을 습득한 결과로 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제17권3호
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• pp.434-440
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• 2004

The aim of this study was to evaluate effects of modified glucomannan ($Mycosorb^{TM}$) on the antioxidant profile of egg yolk and tissues of newly hatched quail after aurofusarin inclusion in the maternal diet. Fifty-four 45 day-old Japanese quail were divided into three groups and were fed a corn-soya diet balanced in all nutrients ad libitum. The diet of the experimental quail was supplemented with aurofusarin at the level of 26.4 mg/kg feed in the form of Fusarium graminearum culture enriched with aurofusarin or with aurofusarin plus $Mycosorb^{TM}$ at 1 g/kg feed. Eggs obtained after 8 weeks of feeding were analysed and incubated in standard conditions of $37.5^{\circ}C$/55% RH. Samples of quail tissues were collected from newly hatched quail. The main carotenoids, retinol, retinyl esters and malondialdehyde were analysed by HPLC-based methods. Inclusion of aurofusarin in the maternal diet was associated with decreased carotenoid and vitamin A concentrations in egg yolk and liver of newly-hatched quail. Furthermore, lipid peroxidation in quail tissues was enhanced. Inclusion of modified glucomannan ($Mycosorb^{TM}$) in the toxin-contaminated diet provided a significant protective effect against changes in antioxidant composition in the egg yolk and liver. It is suggested that a combination of mycotoxin adsorbents and natural antioxidants could be the next step in counteracting mycotoxins in animal feed.

• 한국수산과학회지
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• 제53권2호
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• pp.203-208
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• 2020

This study was carried out to clarify the larvae and juveniles of egg development and autonomous development of Hemibarbus longirostris from Korea, and to obtain basic data for species conservation and seed production. The shape of the egg was circular and sticky. The average size of the eggs was 2.01 mm (n=10). At 185 hours after fertilization, more than 50% of the total embryos were hatched. The newly hatched larvae had an average total length of 8.10 mm (n=5) and had egg yolk in the abdomen. At 3 days after hatching, the larvae absorbed all egg yolk was average total length 8.64 mm. On the 6 days after hatching, the caudal tip of the notochord started to curve upwards was average total length 10.9 mm. At 70 days after hatching, the average total length 37.9 mm. The number of fins was i 8-10 in dorsal fin, iii 7 in the anal fin, and ii 5 in the ventral fin.

• 한국발생생물학회지:발생과생식
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• 제17권3호
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• pp.247-255
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• 2013

The gonadsomatic index (GSI) of mottled skate was the highest in April, GSI and HSI showed a reverse phase for its reproductive cycle. The fish had one pair of egg capsules, having 1 to 7 fertilized eggs, and spawned all the year round. When surveying the reproductive characteristics of females over 63 cm in disc width, we found the spawning peak was between April to June, and the appearance ratio of egg capsules was the highest in May (32.1%). The eggs were hatched at $8^{\circ}C$, $13^{\circ}C$, $18^{\circ}C$, water temperature (12.8 to $24.2^{\circ}C$), and the best hatching temperature was $18^{\circ}C$. The number of fish hatched was 4 to 5 fish/egg capsules, and the hatching rate was 100%. The sex ratios of hatching larvae were 45.5% female and 54.5% male. Therefore this study will provide fundamental data and information for artificial reproduction of the mottled skate.

• 한국수산과학회지
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• 제55권1호
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• pp.23-29
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• 2022

This study was carried out to clarify the egg, larvae and juveniles development of Misgurnus anguillicaudatus, and relationships of M. anguillicaudatus and M. mizolepis, Cobitididae Fishes. The adult fishes were collected in Samsan-cheon, Haenam-gun, Jeollanam-do, Korea and their spawning inducement was carried by ovaprim injections. The egg shape was circular and the size was average 1.12 mm. The eggs were hatched at 61 to 72 h after fertilization. The newly hatched larvae had an average 3.23 mm in total length (TL). At 5 days after hatching, the larvae reached to post larval stage and they were 10.3 mm in TL. At 19 days after hatching, it reached to juvenile stage and was 25.3 mm in TL. The egg size of M. anguillicaudatus was almost same as M. mizolepis but the hatching period of M. anguillicaudatus has taken longer. It was possible for interspecific distinguishability of M. anguillicaudatus and M. mizolepis when their larvae reached to juvenile stage by the development of keel-like ridges.

• 한국가금학회지
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• 제27권3호
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• pp.181-187
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• 2000

This work was designed to investigate the performances of broiler breeder hens upon the addition were vitamin and mineral supplements in feeds. Animals were divided into for feed groups such as control, T$_1$,T$_2$and T$_3$, and each treatment has four replications. All broiler breeder hens were housed individually, and were fed with identical iso-metaboilic energy and iso-protein, except for vitamins and minerals. Different sources and levels of vitamins and minerals were added to the basic feeds according to the treatments. At the end of the experiments, general laying rate(hen days), average egg weight, hatching egg laying rate(Hen day) every day. Hatching egg weight, sterility, embryo mortality, hatching rate and chick weight were examined. Although, early laying rate in all treatment groups were reduced during cold term management, general egg laying rate was increased only T$_3$group which was contanining vitamin C. However, similar results were obtained in the rates of general and hatching egg laying. General egg laying rate were somewhat higher of Control, T$_2$and T$_3$ groups than that of T$_1$group. In addition, the laying rates of general and hatching eggs slightly improved in the T$_3$group rather than those of Control group. Egg weight was reduced with the increasing of laying rate, showing the highest in the T$_3$group. The laying rate showed significantly lower value than those of any other groups. Egg weight was about 65g in T$_3$group. The results of hatching performance for production ability of Broiler breeder hens were fed experimental diet, although the rates of non-hatched and hatched eggs increased in order of Control, T$_1$T$_2$and T$_3$groups. However, the rate of embryo mortality was declined in order Control, T$_1$T$_2$and T$_3$groups.

• 대한수의학회지
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• 제33권2호
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• pp.277-283
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• 1993

In the present study, observations were made on the life-history of Lymnaea viridis under laboratory conditions, involving incubation period of the eggs and their hatching rate, shell length of the newly hatched snails, sexual maturity, size of the snails when the snail produced the first egg-mass, the number of eggs in each egg-mass, egg-laying, ovipostion, growth rate of the snails, and longevity of the snail. At temperatures between $19.8^{\circ}C$ to $22.5^{\circ}C$, incubation period of the eggs occupied 10~12 days, and after beginning of hatching, all young snails emerged completely from the egg-mass within 5 days. The hatching rate was 88%. The average shell length of the newly hatched snails was about 0.064cm. The rate of growth was extraordinarily rapid under good laboratory conditions. When two snails were reared in one culture vessel($20{\times}15{\times}5cm$) with blue-green algae at about $22^{\circ}C$, snail growth was optimal, taking 37 days to reach 1.2cm in shell length. Sexual maturity reached in about 19 days. The size of the snails at sexual maturity was $0.78{\pm}0.05cm$ in length and $0.47{\pm}0.04cm$ in width. The first egg-masses produced were $0.59{\pm}0.22cm$ in length and $0.34{\pm}0.08cm$ in width, and contained 7~38 eggs. The eggs are usually laid in water. The egg-laying was affected by food and temperature. Snails fed with blue-green algae at about $22^{\circ}C$ produced larger egg-masses than the snails fed with fish food at about $26^{\circ}C$. Under conditions of continuous activity and growth, the maximum expectation of life appears to be 109~350(mean 230) days. And the shell length of snails at death were 1.39~1.64cm.

• Asian-Australasian Journal of Animal Sciences
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• 제30권12호
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• pp.1674-1678
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• 2017

Objective: The aim of the study was to evaluate genetic correlations between the behavioural profile and performance in laying hens as an indirect answer to the question whether the observed behavioural responses are associated with increased levels of stress in these birds. Methods: The assessment of birds' temperament was carried out using the novel objects test. The behavioural test was conducted in two successive generations comprising 9,483 Rhode Island White (RIW) birds (approx. 4,700 individuals per generation) and 4,326 Rhode Island Red (RIR) birds (approx. 2,100 individuals per generation). Based on the recorded responses, the birds were divided into two groups: a fearful profile (1,418 RIW hens and 580 RIR hens) and a brave/curious profile (8,065 RIW hens and 3,746 RIR hens). The birds were subjected to standard assessment of their performance traits, including SM, age at sexual maturity; ST, shell thickness; SG, egg specific gravity; EW, mean egg weight; IP, initial egg production; and HC, number of hatched chicks. The pedigree was three generations deep (including two behaviourrecorded generations). Estimation of the (co)variance components was performed with the Gibbs sampling method, which accounts for the discrete character of the behavioural profile denotation. Results: The analyses revealed negative correlations between the performance traits of the laying hens and the behavioural profile defined as fearful. In the group of fearful RIW birds, delayed sexual maturation (0.22) as well as a decrease in the initial egg production (-0.30), egg weight (-0.54), egg specific gravity (-0.331), shell thickness (-0.11), and the number of hatched chicks (-0.24) could be expected. These correlations were less pronounced in the RIR breed, in which the fearful birds exhibited a decline in hatchability (-0.37), egg specific gravity (-0.11), and the number of hatched chicks (-0.18). There were no correlations in the case of the other traits or they were positive but exhibited a substantial standard error, as for the egg weight. Conclusion: To sum up the results obtained, it can be noted that behavioural responses indicating fearfulness, i.e. escape, avoidance, and approach-avoidance may reflect negative emotions experienced by birds. The negative correlations with performance in the group of fearful hens may indirectly indicate a high level of stress in these birds, especially in the white-feathered birds, where stronger performance-fearfulness correlations were found. Fearful birds should be eliminated from breeding by inclusion of the behavioural profile in the selection criterion in the case of laying hens.

• 한국양식학회지
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• 제9권4호
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• pp.339-344
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• 1996

한국산 rotifer, Brachionus plicatilis 내구란의 부화에 미치는 온도($24\~36^{\circ}C$)와 염분($5{\~}30$ ppt)의 영향을 조사하였다. 가장 높은 내구란의 부화율은 $28^{\circ}C$, 15 ppt에서 $85.7{\%}$로 나타났다. 온도 $32^{\circ}C(42.6\~60.5\%)$와 $36^{\circ}C(52.0\~61.4\%)$에서는 염분과 수온에 따른 부화율은 유의적인 차이를 보이지 않았다. 부화시간은 온도가 높을수록 짧게 나타났다. $5^{\circ}C$ 암흑상태로 내구란을 보존할 경우 2일 동안 일시적으로 부화하였다. 그러나 $28^{\circ}C$ 내구란을 보존한 경우, 14일 동안 산발적으로 부화하였다. 또한 부화율은 $28^{\circ}C(58.1\%)$가 $5^{\circ}C(40.2\%)$ 보다 높게 나타났다. 내구란의 건조온도가 시간에 따른 부화율은 $30^{\circ}C$에서 1시간동안 건조한 내구란이 $46.4{\%}$로 가장 높은 부화율을 보였다.