• 한국식품영양과학회지
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• 제15권3호
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• pp.306-312
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• 1986

Demonstration of the highly positive correlation between blood cholestrol levels and heart disease has made consumers wary of the fats in meat, milk and eggs. The egg, as perhaps the single largest common source of cholesterol, has been cited by many members of the medical and scientific world as a food contributing to heart disease. In light of decreasing per capita egg consumption and continuing dietary egg cholesterol controversy, many researchers have focused their efforts on egg nutrition. The results reported, however, are often contradictory. In spite of the disputable scientific evidence, the egg has been labelled (erroneously) as a highly cholesterogenic food. The objective of this presentation is to present a general picture of the problem and discuss our laboratory findings relevant to the problem. An isotope technique was utilized to incorporate $^{14}C$-cholesterol into egg yolk lipoproteins and study the metabolic fate of dietary ovo-cholesterol in rats. Two hundred and fifty micro-curies of 4-$^{14}C$-cholesterol, emulsified in corn oil, were orally administered to five Single Comb White Leghorn laying hens. Eggs were collected, hard-boiled, and the hot dried egg yolk powder (HEY) was prepared. Total radioactivity excreted via feces was determined. The rat groups fed egg yolk powder excreted more than 95% of the ingested ovo-cholesterol, whereas the rat chow group excreted only 47%. No difference was observed between HEY and CEY treatments. Therefore, an unknown lipid factor present in egg folk accelerates cholesterol turnover rate and excretion via feces.

• Asian-Australasian Journal of Animal Sciences
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• 제19권4호
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• pp.582-586
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• 2006

This experiment was conducted to investigate the dietary effect of garlic powder (GP) and copper (Cu) on laying performances and the cholesterol content and quality characteristics of eggs during storage in laying hens. A total of one hundred and eighty, 50-wk-old, Hy-Line Brown layers were divided into 6 groups with 3 replicates per group (10 layers per replicate) and fed one of six diets containing GP 0%, GP 1%, GP 3%, GP 5%, Cu 200 ppm, or GP 3%-Cu 200 ppm for 5 wks. There were no differences in the laying performances and feed intakes bertween treatments. Eggshell strength, eggshell thickness and yolk color were also not affected by feeding of GP and Cu. With increasing dietary GP, Haugh unit was linearly increased after 2 wk of storage (p<0.05). The levels of serum total cholesterol in hens fed diets containing GP or Cu were lower than that of the control (p<0.05), but high density lipoprotein-cholesterol was not influenced by dietary GP or Cu. The content of egg yolk cholesterol from hens fed diets containing GP or Cu was significantly decreased from that of the control, except for the GP 1% group. Based on the results of this experiment, the decrease of Haugh unit during storage was alleviated by feeding of GP. The feeding of GP or Cu alone and in combination altered the cholesterol fractions in serum and reduced the content of egg yolk cholesterol in laying hens.

• Asian-Australasian Journal of Animal Sciences
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• 제23권5호
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• pp.630-639
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• 2010

Immune response and yolk cholesterol are crucial factors for commercial chicken producers. The objectives of this study were to investigate the effect of selenium-enriched Japanese radish sprouts (Se-enriched JRS) and R. capsulatus synergistically on immune response and cholesterol in laying hens. A total of 50 laying hens (20-wk old) were assigned to 5 dietary treatment groups, and fed diets supplemented with 2.5 ${\mu}g/kg$, 5 ${\mu}g/kg$, 10 ${\mu}g/kg$ Se-enriched JRS and 5 ${\mu}g/kg$ Se-enriched JRS+R. capsulatus (0.02%). Egg production and yolk color were significantly improved by the supplementation of Se-enriched JRS+R. capsulatus in the layer diet (p<0.05). Compared to the control, serum cholesterol concentration and triglyceride levels were decreased by all the treatments (p<0.05). After 8-wk of the experiment, supplementation of 5 ${\mu}g/kg$, 10 ${\mu}g/kg$ and Se-enriched JRS+R. capsulatus significantly reduced yolk cholesterol and triglycerides, while the greatest reduction was observed when R. capsulatus was incorporated with Se-enriched JRS. Spleen, bursa and thymus weight were significantly increased by both the 5 ${\mu}g/kg$ and 10 ${\mu}g/kg$ Se-enriched JRS. Compared to the control, supplementation of 5 ${\mu}g/kg$ and 10 ${\mu}g/kg$ Se-enriched JRS significantly increased serum IgG and yolk IgY concentration and foot web index activity by Newcastle Disease Virus (p<0.05). After 4-wk and 8-wk of supplementation, the highest number of leukocytes was observed with Se-enriched JRS+R. capsulatus (p<0.05). The highest concentration of serum and yolk Se was found in Se-enriched JRS plus R. capsulatus treatment. Combined dietary supplementation of Se-enriched JRS and R. capsulatus might be beneficial for better health, disease protection and overall production performance.

• Asian-Australasian Journal of Animal Sciences
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• 제16권8호
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• pp.1165-1170
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• 2003

A total of 250 laying hens were fed a diet containing 0, 1, 2.5 or 5% conjugated linoleic acid (CLA), and 5% Safflower seed oil (SSO) for 5 weeks, and eggs were collected by week to analyse lipid characteristics of egg yolk. Egg yolk from CLA-fed groups showed significant increase in CLA content with increased CLA in the diet. Dietary CLA also increased the ratio of saturated fatty acids and decreased unsaturated fatty acids in the egg yolk. The proportion of myristic, palmitic, stearic and CLA were increased, while those of oleic, linoleic, linolenic and arachidonic acid were decreased. The cholesterol content in egg yolk was significantly decreased by dietary CLA for 5 weeks feeding. After 7 days of feeding, 5% CLA-fed group showed the lowest cholesterol content in egg yolk. CLAfed groups showed significantly lower 2-thiobarbituric acid-reactive substances (TBARS) values compared to control and SSO-fed group after 14 days of storage. No significant differences in TBARS values among CLA-fed groups were observed at the 28 days of storage. Results suggested that lipid oxidation of egg yolk during cold storage could be inhibited by dietary CLA due not only to changes in fatty acid composition but also to the high concentration of CLA in egg yolk.

• 한국가금학회지
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• 제21권2호
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• pp.139-150
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• 1994

Egg cholesterol has been a hot issue in respect of it's effect on health and diseases in human. There is a general recognition that the cholesterol from eggs is similar to that from the other dietary sources in its biochemical functions. Many evidences show that egg yolk increased plasma cholesterol levels at an average rate of 2.3 mg /100 rnL plasma for every 100 mg cholesterol consumed. The elevation of plasma cholesterol could, however, be altered by various dietary factors such as ratios of polyunsaturated fatty acids and saturated fatty acids. Blood cholesterol levels of Korean adults have been raised up to, on the average, 193 and 187 mg /100 mL plasma for men and women, respectively, from 167/5 mg /100 mL in 1980. Furthermore, proportion of hypercholesterolemics(> 210 mg /dL) has been increased up to 23% of the population. These changes in blood cholesterol levels are attributed to the changes of dietary patterns, suggesting the arguement that Koreans are insensitive to changes of blood cholesterol is not right. Egg cholesterol levels have never been successfully reduced to any significant levels even with tremendous amounts of efforts made during last decades. The alternative and the best way to control blood cholesterol level originating from egg consumption appeares to enrich egg fat with omega-3 series fatty acids. Ingestion of the fatty acid group has specific functions to reduce hypertension and prevent various types of cancer as well as to reduce blood cholesterol. Another way to reduce egg cholesterol directly is to produce smaller egg yolk without reducing whole egg size since cholesterol is located only in the yolk. It is important to keep faith with consumers by providing correct informations on eggs, meanwhile efforts need to focus on to improve the quality of eggs as one of the best protein food items.

• Asian-Australasian Journal of Animal Sciences
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• 제20권6호
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• pp.944-947
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• 2007

This study was conducted to study the effects of dietary garlic powder on laying performance, egg traits and blood serum cholesterol level of quails. A total of three hundred quails (Coturnix coturnix japonica) aged nine weeks were used. They were allocated to 3 dietary treatments. Each treatment comprised 5 replicates of 20 quails. The diets were supplemented with 0, 5 and 10 g/kg garlic powder. The experimental period lasted 21 weeks. The addition of garlic powder did not significantly affect body weight, egg production, feed consumption, feed efficiency, egg shell thickness, egg albumen index, egg yolk index and egg Haugh unit. Adding 5 and 10 g/kg garlic powder to the laying quail diets increased egg weight (p<0.01). Egg yolk cholesterol and blood serum cholesterol concentration were reduced with garlic powder supplementation. The results of this study demonstrated that garlic powder addition had a significant cholesterol-reducing effect in serum and egg yolk without adverse effects on performance and egg traits of laying quails.

• 한국가금학회지
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• 제27권2호
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• pp.133-153
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• 2000

The egg's interior quality is one of the most important criteria for commercial producers and consumers. Internal quality is complex, including aesthetic factors such as taste, freshness, nutritional and processing values, and the genetic influences upon these upon these factors ranges from none to considerable. The rate of cholesterol synthesis in the hen is very high compared to other animals and humans. Genetic selection, diet drugs and other chemicals can alter cholesterol concentration in the plasma of laying hen, but attempts to manipulate the cholesterol concentration in the egg yolk are generally unsuccessful since the cholesterol can only be changed to a small extent. Factors which may affect the degree of pigmentation of the yolk include the type of xanthophyll and its concentration in the feed, the feed composition, and the health of the hen. Several feed ingredients interact with carotenoid pigment to improve or reduce their deposition rates in yolks. Egg weight is determined by genetics, body size prior to first egg housing density, environmental temperature, lighting program, total feed consumption, calcium, phosphorus, niacin, water, methionine, total sulfur amino acids, energy, linoleic acid, fat and protein levels. Eggs need to be promote levels. Eggs need to be promoted a versatile commodity and new processed egg items need to be developed. Organic eggs are laid by hens which were raised in chemical and drug frdd environments. There are still difficulties in producing these eggs due to the availability of organic poultry feeds and cost of organic grains.

• Asian-Australasian Journal of Animal Sciences
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• 제21권11호
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• pp.1610-1615
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• 2008

Natto is a Japanese traditional soybean product fermented by Bacillus natto. The effects of dried fermented soybean (natto) supplement on egg production and egg qualities of layer chickens was studied with regard to the effective use of various waste foods in Japan. Dried natto, prepared by heating at $60^{\circ}C$, was added to a basic diet at a level of up to 3%. Forty 166-wk-old layer chickens (Rhode Island Red) were randomly divided into 4 groups and five layer chickens were used in each group with two replicates. Layer chickens in group 1 were fed a basic diet as the control. The remaining 3 groups were fed the basic diet supplemented with dried natto at levels of 1, 2, and 3% (w/w), respectively. The result did not show improvements in egg production or feed conversion ratio of layer chickens even when 3% dried natto was added to the control diet. The egg qualities including egg weight, eggshell strength and thickness, yolk color, yolk weight, albumen height, and Haugh unit were also not improved. However, the feeding of dried natto changed the cholesterol content in the egg yolk. The supplementation of dried natto showed the tendency to decrease the yolk cholesterol after 12-wk of feeding compared to the control diet though it did not change plasma cholesterol levels in the blood. On the other hand, yolk cholesterol decreased significantly after 12-wk of feeding 3% dried natto (p<0.05).

• Journal of Nutrition and Health
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• 제47권6호
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• pp.385-393
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• 2014

Purpose: The aim of this study is to examine the effects of egg consumption and suggest proper guidelines for consumption of eggs by determining the relationship between eggs and cholesterol. Methods: Literature review was conducted on the relationship between nutritional, functional properties of eggs and serum cholesterol, as well as cardiovascular disease. Results: Eggs, which are a good protein food with complete amino acid composition, contain vitamin A, riboflavin, vitamin $B1_2$, folic acid, vitamin D, vitamin E, vitamin K, calcium, iron, choline, selenium, ${\beta}$-carotene, lutein, zeaxanthin, etc. However the egg yolk has a high cholesterol content, which is associated with chronic diseases, including heart disease and hypertension. As a result, its intake is subject to regulation. Outbreak of heart disease by yolk intake can show different results depending on the characteristics of the subjects, amount of egg intake, and the implications of other foods eaten. It is difficult to determine whether eggs are beneficial, as they are the main supplying source for other major nutritive elements as well. Several research studies insist that when cholesterol intake increases by 100 mg, the level of serum cholesterol increases by 2.2~4.5 mg/dL and when serum cholesterol increases by 1%, the risk of heart disease increases by 2%. This indicates that a large intake of eggs can increase the risk of heart disease. Although the cholesterol of egg yolk and serum cholesterol are correlated, it is insufficient to conclude that only cholesterol and not other components are related to heart disease. In fact, other components in egg such as various unsaturated fatty acids and phospholipids could be related as well. Rather than concluding egg as a 'good' or 'bad' food according to its cholesterol content, it is important to define egg as a part of dietary patterns. Conclusion: Generalizing an indiscriminate and uniform amount of egg intake for all seems inadequate. However, patients with diabetes or heart disease should pay particular attention to the amount of egg intake. As for the norm, eating egg with vegetables as a substitute for other animal products seems beneficial.

• Asian-Australasian Journal of Animal Sciences
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• 제16권8호
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• pp.1177-1181
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• 2003

This study investigated the effects of cod liver oil and chromium picolinate on the serum traits and egg yolk fatty acids and cholesterol content in laying hens. One hundred 45-week old single comb white Leghorn laying hens were assigned randomly to four groups. These groups were: (1) control (soybean oil), (2) 1,000 ppb (${\mu}g/kg$) chromium (organic form chromium picolinate) (Crpic), (3) 3% cod liver oil (CLO), and (4) 1,000 ppb chromium with 3% cod liver oil (CLO+Crpic). The experiment was conducted for 40 days. Results indicated that serum triacylglycerol (TG) and cholesterol contents in the CLO group and the serum glucose content in the Crpic group were significantly lower than those in the control group (p<0.05-0.01). The yolk cholesterol content in the CLO and Crpic groups were also lower than the control group (p<0.01). The lipoprotein profile displayed that in the Crpic group, high-density lipoprotein (HDL) and HDL-cholesterol (HDL-C) were significantly higher (P<0.05) than the control group. Meanwhile, low-density lipoprotein+very low-density lipoprotein (LDL+VLDL) and LDL-C+VLDL-C were significantly lower (p<0.05) than the control group. Notably, of all four groups, the CLO group displayed a more profound effect on serum traits and lipoprotein (p<0.05-0.001). Furthermore, the fatty acid composition of the egg yolks presented that C18:2 in the CLO and Crpic groups was significantly lower (p<0.05-0.001) compare to the control. However, only in the CLO group, C18:3, C20:5 and C22:6 were significantly higher (p<0.001) than the control. Only serum glucose and LDL+VLDL showed the CLO${\times}$Crpic interaction (p<0.05), most parameters did not. Therefore, supplemented chromium picolinate or cod liver oil in the diet of laying hens had beneficial effects. However, when these two factors were combined, there was no interaction with most parameters.