• Journal of Food Hygiene and Safety
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• v.4 no.1
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• pp.29-36
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• 1989

In order to investigate the Storage time of chicken eggs, several physico-chemical tests from chicken eggs store at 5, 13 and 27$^{\circ}C$ were examined. Egg samples were collected from six poultry farms. Egg stored at 5$^{\circ}C$ based on the depth of air cell and specific gravity, were all acceptable until 17 days ; on the egg yolk coefficient and pH of the egg white and egg yolk until about 10 days. Egg stored at 13$^{\circ}C$, based on the depth of air cell. were acceptable by about 10 days of storage, but on the other physico-chemical tests by about 7 days. Egg samples stored at room temperature(about 27$^{\circ}C$) base on the depth of air cell, were acceptable by about 5 days of storage ; on the specific gravity by 4 days ; and on the egg yolk coefficient and pH of the egg yolk and egg white by 3 days. The results of this study showed that egg stored at 5$^{\circ}C$ were considered acceptable by 10 days of storage ; at 13$^{\circ}C$ by 7 days ; at room temperature (27$^{\circ}C$) by 3 days.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.957-965
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• 2013

This study simulated the egg vertical distribution of mackerel Scomber japonicus in Korean waters using general numerical models. All eggs were spawned naturally by raising broodfishes (May-June 2013), and the egg specific gravity was measured by a density-gradient column. CTD surveys provided environmental data (e.g., temperature and salinity) in May near Jeju Island, Korea. The egg specific gravity during the early stages ranged from 1.0203-1.0211. In general, the fertilized eggs showed a gradual decline in egg specific gravity until full development of the main organs, with a sudden increase just before hatching. Modeled egg vertical distributions were influenced more by wind speed than by egg buoyancy and vertical structure of the sea water. During calm and normal wind speeds, the eggs were distributed from the surface to 25-m depths. Under strong wind conditions (three times higher than the normal speed), the egg concentration on the surface decreased, and the egg distributional depth was deeper (~50 m).

• Korean Journal of Poultry Science
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• v.44 no.4
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• pp.235-243
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• 2017

This experiment was aimed at investigating the effects of dietary supplementation with fermented rice bran (FRB) or fermented broken rice (FBR) on egg-laying performance, egg quality, blood parameters, and cholesterol level in egg yolk of Hy-Line Brown egg-laying hens. Altogether, 144 Hy-Line Brown egg-laying hens (32-week-old) were randomly allocated to one of 4 dietary treatment groups, with 4 replicates per treatment. Of them, 3 treatments diets were prepared by supplementing the basal diet with 0.1% probiotics (PRO), 1% fermented rice bran (FRB), or 1% fermented broken rice (FBR) at the expense of corn. Hen-day egg production was higher (P<0.05) in PRO and FRB treatment groups than in the basal treatment groups. However, feed intake, egg weight, egg mass, and feed conversion ratio did not differ among the treatment groups. Additionally, supplementation with FRB or FBR did not affect eggshell strength, eggshell thickness, egg yolk color, and Haugh unit during the feeding trial. There was no significant difference in leukocyte count. Total cholesterol level was lower (P<0.05) in the FRB treatment group than in the basal treatment groups. Asparate aminotransferase, alanine transferase, glucose, and albumin levels were unaffected by dietary supplementation with FRB or FBR. Egg yolk cholesterol level was lower (P<0.05) in the FRB and FBR treatment groups than in the basal treatment groups. In conclusion, dietary supplementation with FRB or FBR improved egg-laying performance, and reduced the levels of total serum cholesterol and cholesterol in egg yolk of Hy-Line Brown egg-laying hens.

• Food Science of Animal Resources
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• v.33 no.5
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• pp.672-677
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• 2013

The aim of this study was to develop sample preparation method and evaluate the exact cholesterol content in egg and egg powder purchased from Korean markets, and to determine whether significant differences exist among various egg products, since a variety of products are available in Korean markets and there are no recent databases for cholesterol. To evaluate the cholesterol content in chicken egg sold in Korean local market, a simple method using non-heated saponification to determine cholesterol for emulsified foods was applied. The results of recovery for egg and egg powder were in a range of 92.4-105.0%, with a relative standard deviation between 1.1% and 2.8% by using gas chromatography-flame ionization detector. Therefore, the total cholesterol content in whole egg was estimated between 160.8 and 226.3 mg/egg (AV(average) $186.8{\pm}3.5$), which is similar or lower than previously reported levels. The value for cholesterol in egg powder was estimated between 2.94 and 3.49 mg/g (AV $3.23{\pm}0.15$). We suggested method that can be applicable to chicken egg and egg powder matrix as providing rapid and accurate determination of cholesterol in egg and egg powder. This information will be helpful for processed food producers for deciding food labels of cholesterol content.

• Development and Reproduction
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• v.1 no.1
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• pp.91-97
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• 1997

In order to study the reproductive physiology of Sand ell(Hypoptichus dybowskii) catched at kangwon-do, Wooamjin Bay, spawning and egg development were investigated in April and May, 1996. The observed spawning period was from the middle of April to the end of May with the water temperature above $8^{\circ}$C. Body size and colouration were distinguished between male and female. The type of testicular structure is lobular, and the ovary is a pair of sac-sahaped covering with a fibromuscula capsule and comprising a mature egg of average 86. The unfertilzed egg are demersal and adhesive, and their diameter were 1.65-1.95 mm. the colour of yolk is light yellow and contained a lot of tiny oil globules. The average spawned egg was 62 in sargasso weeds. Hatching was observed in 12 days after fertilization with the water temperature of 14 ${\pm}1^{\circ}$C. The average size of larva after hatching was 6.85${\pm}$0.23mm in total length, and larva were containing yolk including globule.

• Journal of environmental and Sanitary engineering
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• v.22 no.3
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• pp.27-33
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• 2007

M. incognita are plant-parasite nematode that cause severe damage to the crops. P. lilacinus are renowned for inhibitation of development of M. incognita's egg. We make a study for enzymatic examining the cause closely that P. lilacinus suppress development of M. incognita's egg by parasiting. The research result is explained the place below. 1. The egg that is exposed to co-enzymes which are cultured in the broth culture starts to change the membrane of egg from 3days. And in 10days, that membrane completely disappear. These are observed through light microscope. Therefore, we know that M. incongnita are controlled by extracellular lytic enzymes that are produced by P. lilacinus. 2. Through scanning electron microscope, we can find that the egg that is attacked by P. lilacinus loses it's membrane gradually, and that loss of the membrane causes transform, which suppresses the development of egg.

• Journal of Aquaculture
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• v.10 no.3
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• pp.357-362
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• 1997

In order to obtain the basic information for seedling production of flatfish, Limanda herzensteini, the influence of water temperature and salinity on egg development was investigated. The desirable water temperature for egg hatching was9~$15^\circC$. The time of egg development was shorter with higher water temperature. The relationships between the water temperature (T:$^\circC$) and the required time (t:hour) from egg to each development stage were given as follows ; 8-cell : 1/t=0.0284T-0.0554 (r=0.9999) Morula : 1/t=0.0137T-0.0527 (r=0.9998) Kupffer's vesicle : 1/t=0.0035T-0.0133 (r=0.9762) Hatching : 1/t=0.0012T-0.0007 (r=0.9981) Biological mimimum temperature for the egg development was estimated to the be $2.6^\circC$ in average. The salinity which showed over 50% survival rate from fertilized egg to hatching was 35~$38\textperthousand$.

• Korean Journal of Poultry Science
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• v.47 no.1
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• pp.39-48
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• 2020

The present study intended to analyze and detect any possible shortcomings in the current egg distribution system in Korea through a questionnaire. The institutional system and cases of operation thereof in advanced countries such as the USA, Japan, and Germany for the development of the egg distribution industry in Korea. The results revealed the following issues: absent pricing system, ineffective egg distribution, and difficulty in balancing supply and demand. Suggestions for addressing these issues and the subsequent improvement were based on cases found in the instated systems of advanced countries, and were given as follows: (i) The existing GP Center needs to be separated from the farms of laying hens, and the current institutional system and its operations need to be improved and should be approved by the government. Parallel to the institutional improvement, establishing a distribution system centered on the GP Center would be desirable. (ii) Egg pricing regulations are needed as a standard to determine the price of eggs. (iii) The reinforcing control standards and securing means for egg preservation are pertinent to each stage of egg distribution and should take into account environmental factors such as egg preservation temperature to guarantee high hygiene standards and egg safety.

• Korean Journal of Poultry Science
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• v.39 no.1
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• pp.39-43
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• 2012

This study was conducted to investigate the effect of dietary supplementation levels of spinach powder and extract on performance, egg quality and lutein content in egg yolk. Laying hens were subjected to one of the following treatments; C, basal diet (BD); T1, BD + 1 ppm lutein from spinach powder; T2, BD + 1 ppm lutein powder from spinach extract; T3, BD + 2 ppm lutein powder from spinach extract; T4, BD + 2 ppm lutein from spinach extract. As a result, performance of laying hens was no significant difference among treatments. T4 had a significantly (p<0.05) higher egg yolk color than the other treatments. As from the lutein content in egg yolk, T4 had a significantly (p<0.05) higher content than the other treatments. Finally, these results suggested that the dietary supplementation for lutein-rich egg production, lutein concentration must be higher than a minimum of 2 ppm. Also, dietary with lutein extract from raw materials was appropriate for lutein-rich egg production than dietary with raw materials.

• Development and Reproduction
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• v.18 no.1
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• pp.25-31
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• 2014

This study was investigated spawning behavior, structure of egg masses and egg development in Aplysia kurodai inhabiting the coastal waters of Jeju Island, Korea. The mating and courtship behavior of A. kurodai occurred in the form of unilateral copulating with chain formation. In chain copulation, only the first animal acted as a female; the second and succeeding animals acted as males (sperm donors) to the animals in front and as females to the animals behind. The fertilized eggs were packaged in capsules that are embedded in jelly to form a cylindrical string called an egg masses. The number of capsule per cm of the egg masses was 55 to 60 capsules and each capsule within the egg masses held 15 to 25 eggs. After spawning, the egg masses were bright yellow or orange in color. This egg masses color not changed until embryos developed into trochophore stage. Thereafter, as embryo developed from trochophore stage to veliger stage the egg masses color became brownish. The fertilized eggs were spherical, with a diameter of approximately $80{\pm}1{\mu}m$ at spawning. At 5 to 6 days after spawning, the embryo developed into trochophore stage and began to rotate within the egg capsule. In the trochophore stage, the precursor of the velum, called the prototroch or prevelum, developed. At 10 days after spawning, the prevelum is transformed into the velum, and the trochophore developed into veliger stage. Between 10 to 15 days after spawning, the veligers broke out of the egg capsule, and hatched as free-swimming larvae.