• Asian-Australasian Journal of Animal Sciences
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• 제5권3호
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• pp.461-464
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• 1992

A survey of the cholesterol content of eggs obtained from commercial sources in Korea was conducted. Eggs from 17 different strain birds were obtained from the Poultry Random Sample Test Station at Ansung, Kyonggi province. Yolk cholesterol contents, determined by the colorimetric procedure, were obtained from three consecutively laid eggs from birds of about 63 weeks of age. The overall mean of cholesterol value was 17.25 mg/g of wet yolk and ranged from 16.40 to 18.18 mg/g yolk. Analysis of t-test between white shell eggs and brown shell eggs showed no difference in cholesterol content: however, the white shell eggs were somewhat high in cholesterol (17.41 vs. 17.08 mg/g yolk). Significant differences (p<0.05) were found in yolk cholesterol contents among strains within the breed.

• Asian-Australasian Journal of Animal Sciences
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• 제16권12호
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• pp.1799-1803
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• 2003

The possibility of lycopene affecting egg yolk pigmentation was studied with lycopene diets containing 0, 4, 8, and $12{\mu}g/g$ meal, respectively. The addition of lycopene above $4{\mu}g/g$ meal significantly improved yolk color after four days of supplementation. The transfer of lycopene into egg yolk was confirmed by thin layer chromatography, and high-performance liquid chromatography-mass spectrometry (HPLC-MS). The deposition rate of lycopene into egg yolk was approximately 2%, which was quantitatively determined using a HPLC with a UV detector. The result indicates that lycopene is a good candidate for egg yolk pigmentation and for making functional eggs.

• Asian-Australasian Journal of Animal Sciences
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• 제28권4호
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• pp.538-543
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• 2015

This experiment was conducted to measure the effects of olive leaf powder on performance, egg yield, egg quality and yolk cholesterol level of laying hens. A total of 120 Lohmann Brown laying hens of 22 weeks old were used in this experiment. The birds were fed on standard layer diets containing 0, 1%, 2%, or 3% olive leaf powder for 8 weeks. Egg weight and yield were recorded daily; feed intake weekly; egg quality and cholesterol content at the end of the trial. Olive leaf powder had no effect on feed intake, egg weight, egg yield and feed conversion ratio (p>0.05) while olive leaf powder increased final body weight of hens (p<0.05). Dietary olive leaf powder increased yellowness in yolk color (p<0.01) without affecting other quality parameters. Yolk cholesterol content was tended to decrease about 10% (p>0.05). To conclude, olive leaf powder can be used for reducing egg yolk cholesterol content and egg yolk coloring agent in layer diets.

• 한국가금학회지
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• 제28권3호
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• pp.187-192
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• 2001

전체 난중에 대하여 난황의 구성비율이 낮은 저난황란을 생산하는 계통을 선발하고자 29주령, 33주령, 38주령 및 43주령시에 계란의 주요 경제형질들을 측정하였던 바 그 결과를 요약하면 다음과 같다. 시험 시작시인 29주령 전후 연속 3일동안에 생산된 계란들로부터 난황:난백의 비율을 기초로하여 분류된 두 난황군 중 저난황군은 고난황군에 비해서 전체적으로 난중에 대한 난황의 비율 및 난황:난백의 비율은 더 낮고, 난황의 무게는 더 가벼웠던 반면에,평균난중, 난백의 무게 및 난각의 무게는 유의 (P<0.05)하게 더 무거웠다. 각 시험주령 전후 연속 3일 동안에 생산된 계란 상호간 두군 평균 난황:난백 비율의 상관관계는 상당히 높은(P<0.01 ∼ 0.001) 정(+)상관 관계를 나타냈고, 각 란황군별로 4개 시험주령을 합한 전체 평균 난황:난백 비율의 상관관계도 또한 두군 모두 높은 유의성 (P<0.001)을 나타냈다. 난중에 대한 난백의 무게, 난황의 무게 및 난황:난백 비율의 회귀분석의 결과는 두 난황군 모두 난백의 무게는 난황의 무게보다 전체 난중의 변화에 더욱 밀접한 상관관계를 나타냈으며, 전체 난중에 대한 난황:난백 비율의 상관관계는 난중에 대한 난백의 무게 혹은 난황의 무게와의 상관관계보다는 상대적으로 두 난황군 모두 낮은 편이었다.

• 대한수의학회지
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• 제41권1호
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• pp.29-35
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• 2001

The protective effects of egg yolk atibodies obtained from chickens immunized with fimbrial antigens from ETEC 987P were evaluated in 14 and 21 d old pigs in which ETEC diarrhea was induced. For the Exp. 1, eight early-weaned pigs($5.00{\pm}0.5kg$ average BW and 14 d average age) and eight weaned pigs($6.00{\pm}0.5kg$ average BW and 21 d average age) were used to examine influence of egg yolk antibodies on growth performance and resistance to ETEC 987P infection. Dietary treatments included 1) administered of commercial egg yolk(14 d of age; CEY14), 2) administered of egg yolk antibodies(14 d of age; EYA14), 3) administered of commercial egg yolk(21 d of age; CEY21), 4) administered of egg yolk antibodies(21 d of age; EYA21). The 14 and 21 d old pigs were challenged with 2 ml of ETEC 987P at a dose of $10^{10}\;CFU\;ml^{-1}$ per weaned pigs. Weaned pigs treated with egg yolk antibodies recovered and pigs treated with egg yolk antibodies tended to increase average daily gain(P<0.05). Also, EYA12 and EYA21 treatments were reduced coli-form bacteria concentration and increased Lactobacilli sp. concentration from feces. For the Exp. 2, sixteen weaned pigs($6.00{\pm}0.5kg$ average daily gain BW and 21 d average age) were used to examine influence of yolk or white from egg containing antibodies on growth performance and resistance to ETEC 987P infection. Dietary treatments included l) administered of commercial egg yolk(CEY), 2) administered of commercial egg white(CEW), 3) administered of egg yolk antibodies(EYA), 4) administered of egg white antibodies(EWA). Pigs treated only with EYA showed signs of recovery. Also, EYA treatment showed the best average daily gain without significant differences (P>0.05). EYA treatment was reduced coli-form bacteria concentration increased and Lactobacilli sp. concentration from feces. In conclusion, egg yolk antibodies have protective effects from pigs in which ETEC diarrhea was induced.

• 한국발생생물학회지:발생과생식
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• 제22권3호
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• pp.213-223
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• 2018

Ultrastructural studies on oocyte differentiation and vitellogenesis in the oocytes of female Kareius bicoloratus were investigated by transmission electron microscopy. The Golgi complex in the cytoplasm is involved in the formation of yolk vesicles that contain yolk carbohydrates in the yolk vesicle of oocytes in the early vitellogenic phase. In this phase, many pinocytotic vesicles (PVs), which are formed by pinocytosis, contain yolk precursors (exogenous substances). These substances are associated with exogenous heterosynthetic vitellogenesis. In yolked oocytes in the late vitellogenic phase, two morphologically different bodies, which formed by modified mitochondria, appear in oocytes. One is a multivesicular body (synthesized by autosynthetic vitellogenesis), and the other is a yolk precursor (an exogenous substance formed by heterosynthetic vitellogenesis). The multivesicular bodies (MVB) are taken into the yolk precursors (YP) and are transformed into primary yolk globules. However, after the YP mix with exogenous PVs near the zona pellucida, they are transformed into primary yolk globules. Vitellogenesis of this species occurs via endogenous autosynthesis and exogenous heterogenesis. Vitellogenesis occurs through endogenous autosynthesis, which involves the combined activity of the Golgi complex, mitochondria and MVB formed by modified mitochondria. However, heterosynthesis involves pinocytotic incorporation of extraovarian precursors (such as vitellogenin in the liver) into the zona pellucida (via granulosa cells and thecal cells) of the yolked oocyte.

• Food Science and Biotechnology
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• 제15권2호
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• pp.189-195
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• 2006

A study was conducted to develop optimal conditions for a large-scale, sequential separation method for value-added components from egg yolk. Starting with liquid egg yolk, immunoglobulin Y (IgY), phospholipids, and neutral lipids were extracted sequentially using water, ethanol, and n-hexane. The remainder was yolk proteins. Adjusting the pH of diluted egg yolk to pH 5.0-5.2 decreased phospholipids content in the supernatant after centrifugation, which was very important for preventing clogging problem of ultrafiltration filters during the subsequent concentration step for IgY separation. Extraction of precipitants after centrifugation with four volumes of 100% ethanol once removed most of the phospholipids and the purity of phospholipids was more than 85% (wt.) after drying. The subsequent extraction of precipitant from ethanol extraction with four volumes of hexane 3 times removed neutral lipids almost completely and resulted in a high protein product with minimal lipids. The sequential separation method is considered to be advantageous for large-scale separations of many valuable components from egg yolk.

• 한국가금학회:학술대회논문집
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• 한국가금학회 2000년도 춘계 산학협동 심포지움 Proceedings
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• pp.23-36
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• 2000

Hurdle technique was used to remove cholesterol efficiently from liquid egg yolk. The quality of the low cholesterol egg products from the process were evaluated. From the 75 % cholesterol reduced egg yolk through $\beta$-cyclodextrin treatment. 2 times weight of soy bean oil was added to the egg yolk and homogenized followed by centrifuged to be maximized to remove cholesterol. When the pH of the yolk was adjusted to 9, 92 % of cholesterol was removed while 95.4 % of cholesterol was removed when 3 times weight of soy bean oil was added to the egg yolk. As the results of application of supercritical carbon dioxide extraction to the 75 % cholesterol reduced egg yolk through ${\beta}$-cyclodextrin treatment, 92.5 % of the cholesterol was removed from the egg yolk at $35^{\circ}C$, 4,500 psi, for 4 hours under co-solvent. The quality characteristics of the produced low cholesterol egg products were analysed. The cholesterol reduced egg yolk produced from ${\beta}$-cyclodextrin and soy bean oil treatment showed the lower emulsion capacity compared with control. The fatty acid composition of the cholesterol reduced egg yolk produced from ${\bet}a$-cyclodextrin and soy bean oil treatment showed increased C18:2 and C18:3 compared with control while decreased C16:1 and C18: 1 compared with control. The saponification method with extracting solvent of hexane showed that cholesterol concentration was 28.1 %. The quantity of hydrolysis solution(95 % ethanol : 33 % KOH = 94 : 6) was varied from 40 to 80 times of sample weights and the cholesterol concentration of 35.7 % was the highest result in the 60 times(v/w) hydrolysis solution. Cholesterol concentration of 35.7 % was recovered at the first trial with saponification method. but it could be improved up to 95.7 % after 4 times repetitive purification.

• Asian-Australasian Journal of Animal Sciences
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• 제22권2호
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• pp.254-259
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• 2009

An experiment was conducted to evaluate the effect of different levels of extracted pigment from Dietzia natronolimnaea biomass as a source of canthaxanthin in comparison with synthetic canthaxanthin on egg yolk pigmentation. The experiment used a completely randomized design (CRD). A total of 63 laying hens, 68 weeks old, were used and the birds were allotted to 7 dietary treatments with each treatment replicated three times with three hens per replicate. Treatments consisted of 3 levels of synthetic canthaxanthin (4, 8 and 16 ppm), 3 levels of extracted pigment from D. natronolimnaea biomass (4, 8 and 16 ppm) and control. Changes in yolk color were determined in 2 eggs taken at random, during the four week experimental period from each replicate. Supplementation of extracted pigment from D. natronolimnaea biomass had a significant effect on the color of egg yolks (p<0.05). Yolk color score of the control group was 6.83 in BASF color fan and the yolk color score of different extracted pigment levels was 11.00, 12.50 and 14.50, respectively. The yolk colors of different levels of synthetic canthaxanthin were 12.00, 14.00 and 15.00, respectively. The effect of pigment supplementation on egg yolk color was better explained by polynomial response curves. The $R_{2}$ indicated that for 3 supplementation levels of each pigment studied, over 90% of the color variation could be explained by the pigment concentration. The egg yolk color after 15 and 30 days of storage was not significantly different, but boiling reduced egg yolk color significantly (p<0.05).

• Asian-Australasian Journal of Animal Sciences
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• 제15권6호
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• pp.783-788
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• 2002

Bovine yolk sac at day 24 of pregnancy, and placental membranes (chorion and allantois) from days 70 and 100 of pregnancy were isolated and cultured in a modified minimum essential medium in the presence of $[^{35}S]$methionine. Proteins synthesized and secreted by isolated bovine yolk sac, chorion and allantois were analyzed by fluorography of two-dimensional polyacrylamide gel electrophoresis. Serum-like proteins,transferrin, ${\alpha}$-fetoprotein, ${\alpha}$1-antitrypsin and ${\alpha}$1-acid glycoprotein,were the major protein products of yolk sac. A 21 kDa protein produced by yolk sac was identified immunochemically as retinol-binding protein (RBP). Chorion and allantios from days 70 and 100 of pregnancy were active in protein synthesis and secretion. Both chorion and allantois did not secret serum-like proteins but secreted a number of neutral-to-acidic proteins including RBP. Secretory proteins produced by the yolk sac, chorion and allantois may play important roles in the embryonic development and the successful outcome of pregnancy. Antiserum against bovine placental RBP was employed to the immunocytochemistry by immunoperoxidase method. Immunoreactive RBP was localized in epithelial cells and island-like cell clones of yolk sac. Immunostaining for RBP was detected in simple columnar epithelium of chorion and in simple squamous epithelium of allantois. In the present study, proteins synthesized and secreted by yolk sac at day 24 of pregnancy, chorion and allantois from days 70 and 100 of pregnancy were characterized In addition, RBP was localized in yolk sac, chorion and allantois by immunoperoxidase method. The immunoperoxidase method has been proven to be a very effective technique to identify the cellular source of protein synthesis in extraembryonic membranes.