• Korean Journal of Poultry Science
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• v.24 no.4
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• pp.169-177
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• 1997

Four experiments were conducted to investigate the association of yolk cholesterol level with egg trails, serum cholesterol level, body weight (BW) and breed differences and other variations. Athens Canadian Randombred (ACRB), a commercial layer breed (CL) and two commercial broiler breeds (BR1 and BR2) were used for this studies. Egg weight of CL was heavier by 8.7g per egg than that of ACRB, but the yolk percentage and yolk cholesterol were lower by 7.8％ per egg and 5.5mg per g yolk than those of ACRB, respectively. Yolk cholesterol content had no significant relation with the average egg weight or yolk weight in ACRB, but was significantly related with yolk fat level. However, yolk cholesterol level in CL showed inverse relationship with other egg traits compared to that of ACRB. In the CL female group, the association of yolk cholesterol level with BW was significant(P$\leq$0.05) at 25 weeks of age, but was not significant different at 26 wks of age. The relationship of yolk cholesterol with serum was not significantly different at 25 weeks of age, whereas it showed significant negative(-) correlation coefficient(P$\leq$0.01) at 26 wks of age. The association of yolk cholesterol level with egg age in CL population was not high comared to that of other treatments. The serum cholesterol content of CL was not significantly different with BR1 and BR2 populations at 25 weeks of age, but was significantly(P$\leq$0.05) higher than that of BR1 or BR2 at 26 weeks old.

• Food Science of Animal Resources
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• v.26 no.4
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• pp.517-524
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• 2006

We investigated the effect of different kinds of dietary fats on the fatty acid composition, cholesterol content and quality of hens' eggs. The Haugh units, breaking strength, shell thickness and yolk color were not significantly different among the test groups. The type of dietary fat fed each test group notably altered the polyunsaturated fatty acid composition and cholesterol content of egg yolk. The n-6 fatty acid content of egg yolk was highest in the corn oil fed group being 31.61%, and this tended to decrease in the tallow, linseed oil and fish oil fed groups(P<0.05) in that order. The n-3 fatty acid content of egg yolk tended to increase in the linseed oil and fish oil fed groups with values of 9.74% and 5.16%, respectively(p<0.05). The increase of n-3 fatty acids in the yolk resulted in a reduced cholesterol content of the eggs. The cholesterol content ranged from $15.98{\sim}18.37mg/g$ of yolk or $227{\sim}261mg/60g$ of egg(p<0.05). The cholesterol content of egg yolk was highest in the tallow fed group, and significantly reduced to 13.01% in the fish oil group, 11.49% in the linseed oil group and 6.91% in the corn oil group(p<0.05). This result suggests that it is possible to reduce the cholesterol content or to increase the n-6 and n-3 polyunsaturated fatty acid contents in eggs by the manipulation of dietary fats.

• KOREAN POULTRY JOURNAL
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• v.20 no.5 s.223
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• pp.110-114
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• 1988

난황 섭취와 콜레스테롤의 상승과의 관계는 개인에 따라 다르고, 일반적으로 매일 1$\~$2개 정도의 섭취는 거의 영향을 미치지 않는다.

• Korean Journal of Poultry Science
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• v.29 no.2
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• pp.81-88
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• 2002

The objective of this study was to investigate the line-by-feed additive interaction on egg traits and yolk cholesterol level in laying hens. Hy-line W-98 (white shell line) and Hy-line Brown (brown shell line) were used as experimental stocks and three groups were assigned in each line. The age of hens used in this study were from 40- to 46-wk-old. Two different levels of chitosan were also used as additive in chicken diet. The first (CH$_{30}$) and second (CH$_{60}$) experimental groups were fed basal diet added 30mg and 60mg chitosan/kg feed, respectively. And the control group (CON) hens were fed with basal diet only. The eggs were collected and analyzed at the end of 40, 42, 44, and 46-wk-old. In the mean egg weight, the CH$_{30}$ in Hy-line Brown was significantly heavier (P<0.05) than CON, but the CH$_{30}$ in Hy-line W-98 was significantly lighter (P<0.05) than CON. Whereas, the mean egg weight did not significantly differ between CH$_{60}$ and CON in both line. The mean albumen percentage in Hy-line Brown did not show significant between experimental groups and control group. On the other hand, the mean albumen percentage of CH$_{60}$ in Hy-line W-98 was significantly lower (P < 0.05) than that of CON, but there was no significantly different between CH$_{30}$ and CON. In the mean yolk percentage, it showed a reverse trend as shown in the mean albumen percentage; there were significantly higher (P<0.05) in CH$_{60}$ than in CON fur the Hy-line W-98, and higher in CH$_{30}$ than in CON for the Hy-line Brown. However, the mean shell percentages did not significantly differ between experimental groups and control group in both lines. In the mean yolk cholesterol levels, the CH$_{30}$ and CH$_{60}$ in both lines were lower by 0.46 mg ∼2.80 mg per gram yolk than CON. Although the interaction effect of line-by-supplementing level of chitosan in hens diet on the pooled mean of yolk cholesterol level was no significant, it showed a highly significant interaction (P<0.01) at three of four experimental ages.

• Journal of Animal Science and Technology
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• v.48 no.1
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• pp.59-68
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• 2006

This experiment was conducted to investigate the effects of dietary supplementation of activated charcoal (AC) mixed with wood vinegar on performance and egg quality in laying hens. A total of one hundred ninety two, 56-wk-old Lohmann brown laying hens were divided into four groups, consisting four replicates of 12 birds each and fed one of the four experimental diets containing AC 0%, AC 0.5%, AC 1%, AC 2% for 5 wks. The blood profiles and contents of total lipid and cholesterol, fatty acid profiles in egg yolk were determined. There were no significant differences in laying performance, feed intake and vitelline membrane strength among the treatments. The eggshell breaking strength and Haugh unit were significantly increased in 2% AC group compared to the other groups (P<0.05). Egg yolk index in 2% AC group was significantly higher (P<0.05) than those of the control and 0.5% AC group and yolk color was significantly improved by the dietary AC (P<0.05). The levels of serum total cholesterol, HDL-cholesterol and enzyme activities were not influenced by feeding AC. Total lipid of egg yolk in 1 % and 2% AC groups was significantly decreased (P<0.05) compared to that of the control, although there was no significant difference in yolk cholesterol. In conclusion, the addition of activated charcoal with wood vinegar in layer diet resulted in improving egg quality by means of enhancing eggshell breaking strength, Haugh unit, yolk index and yolk color.

• Korean Journal of Poultry Science
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• v.34 no.3
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• pp.223-229
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• 2007

This study was conducted to evaluate effects of dietary pine cone meal on egg production, egg quality, serum cholesterol and cholesterol content and fatty acid composition of egg yolk in laying hens. The total of 252 (51-wks) Hy-line brown commercial hens were used for 5 weeks. Dietary treatments included 1) T1 (basal diet + 1% cottonwood sawdust), 2) T2 (basal diet + 0.5% cottonwood sawdust + 0.5% pine cone meal) and 3) T3 (basal diet + 1% pine cone meal). During the overall period, there was no significant difference in egg production, egg weight and egg quality among the treatments. Lipids profile(total, HDL, LDL cholesterol and triglyceride) in serum was not affected by treatments. Egg yolk cholesterol was not significantly different among the treatments. In fatty acid contents of yolk, C18:3 was higher in T1 treatment than T3 treatment(P<0.05). Total SFA, PUFA, MUFA and UFA/SFA were not significantly different in experimental period. In conclusion, dietary supplementation of pine cone meal affected C18:3 fatty acid content of yolk in laying hens, without any adverse effect on egg production.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2005.05a
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• pp.348-352
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• 2005

본 연구는 가교화 ${\beta}-CD$를 제조하여 난황의 콜레스테롤 제거 최적 조건을 확립하고, 가교화 ${\beta}-CD$를 재활용하는 것을 목적으로 하였다. 가교화 ${\beta}-CD$를 20% 첨가하여 동량의 증류수를 혼합한 난황을 교반온도 $40^{\circ}C$, 교반시간 30분, 교반속도 800rpm으로 처리할 때, 평균92.70%라는 높은 제거율을 보였고, 10회 재활용 결과 평균 88.77%의 재활용률을 보였으며, 8회 이후에는 유의적으로 감소하였다.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2003.11a
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• pp.80-81
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• 2003

The aim of this study was the evaluation of the dietary effect of garlic powder(GP) and copper(Cu) on productivity, storage qualify of egg and egg yolk cholesterol in laying hens. 52-week-old layers were fed one of six diets containing 0 ％GP(Control), 1·3·5 ％ GP, 200 ppm Cu, 3 ％ GP-200 ppm Cu, respectively, for 5 wks. There were no differences in egg production performances and feed intake among treated groups. With the increase in dietary GP levels, the Haugh unit were higher linearly after 7-d and 14-d storage. The cholesterol contents of serum and egg Yolk in 3 ％ GP-200 ppm Cu groups were significantly lower than those of Control.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 1997.11a
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• pp.152-152
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• 1997

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 1999.10a
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• pp.120-120
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• 1999