• Asian-Australasian Journal of Animal Sciences
• /
• v.9 no.1
• /
• pp.1-25
• /
• 1996

The pathogenesis of atherosclerosis can not be summarized as a single process. Lipid infiltration hypothesis and endothelial injury hypothesis have been proposed and investigated. Recent developments show that there are many points of potential interactions between them and that they can actually be regarded as two phases of a single, unifying hypothesis. Among the many risk factors of atherosclerosis, plasma homocysteine and lipoprotein(a) draw a considerable interest because they are independent indicators of atherogenicity. Triglyceride (TG)-rich lipoproteins (chylomicron and VLDL) are not considered to be atherogenic but they are related to the metabolism of HDL cholesterol and indirectly related to coronary heart disease (CHD). LDL can of itself be atherogenic but the oxidative products of this lipoprotein are more detrimental. HDL cholesterol has been considered to be a favorable cholesterol. The so-called 'causalist view' claims that HDL traps excess cholesterol from cellular membranes and transfers it to TG-rich lipoproteins that are subsequently removed by hepatic receptors. In the so-called 'noncausalist view', HDL does not interfere directly with cholesterol deposition in the arterial wall but instead reflects he metabolism of TG-rich lipoproteins and their conversion to atherogenic remnants. Approximately 70-80% of the human population shows an effective feedback control mechanism in cholesterol homeostasis. Type of dietary fat has a significant effect on the lipoprotein cholesterol metabolism and atherosclerosis. Generally, saturated fatty acids elevate and PUFA lower serum cholesterol, whereas MUFA have no specific effect. EPA and DHA inhibit the synthesis of TG, VLDL and LDL, and may have favourable effects on some of the risk factors. Phospholipids, particularly lecithin, have an antiatherosclerotic effect. Essential phospholipids (EPL) may enhance the formation of polyunsaturated cholesteryl ester (CE) which is less sclerotic and more easily dispersed via enhanced hydrolysis of CE in the arterial wall. Also, neutral fecal steroid elimination may be enhanced and cholesterol absorption reduced following EPL treatment. Antioxidants protect lipoproteins from oxidation, and cells from the injury of toxic, oxidized LDL. The rationale for lowering of serum cholesterol is the strong association between elevation of plasma or serum cholesterol and CHD. Cholesterol-lowing, especially LDL cholesterol, to the target level could be achieved using diet and combination of drug therapy. Information on the link between cholesterol and CHD has decreased egg consumption by 16-25%. Some clinical studies have indicated that dietary cholesterol and egg have a significant hypercholesterolemic effect, while others have indicated no effect. These studies differed in the use of purified cholesterol or cholesterol in eggs, in the range of baseline and challenge cholesterol levels, in the quality and quantity of concomitant dietary fat, in the study population demographics and initial serum cholesterol levels, and clinical settings. Cholesterol content of eggs varies to a certain extent depending on the age, breed and diet of hens. However, egg yolk cholesterol level is very resistant to change because of the particular mechanism involved in yolk formation. Egg yolk contains a factor of factors responsible for accelerated cholesterol metabolism and excretion compared with crystalline cholesterol. One of these factors could be egg lecithin. Egg lecithin may not be as effective as soybean lecithin in lowering serum cholesterol level due probably to the differences of fatty acid composition. However, egg lecithin may have positive effects in hypercholesterolemia by increasing serum HDL level and excretion of fecal cholesterol. The association of serum cholesterol with egg consumption has been widely studied. When the basal or control diet contained little or no cholesterol, consumption of 1 or 2 eggs daily increased the concentration of plasma cholesterol, whereas that of the normolipemic persons on a normal diet was not significantly influenced by consuming 2 to 3 eggs daily. At higher levels of egg consumption, the concentration of HDL tends to increase as well as LDL. There exist hyper-and hypo-responders to dietary (egg) cholesterol. Identifying individuals in both categories would be useful from the point of view of nutrition guidelines. Dietary modification of fatty acid composition has been pursued as a viable method of modifying fat composition of eggs and adding value to eggs. In many cases beneficial effects of PUFA enriched eggs have been demonstrated. Generally, consumption of n-3 fatty acids enriched eggs lowered the concentration of plasma TG and total cholesterol compared to the consumption of regular eggs. Due to the highly oxidative nature of PUFA, stability of this fat is essential. The implication of hepatic lipid accumulation which was observed in hens fed on fish oils should be explored. Nutritional manipulations, such as supplementation with iodine, inhibitors of cholesterol biosynthesis, garlic products, amino acids and high fibre ingredients, have met a limited success in lowering egg cholesterol.

• Korean Journal of Poultry Science
• /
• v.41 no.1
• /
• pp.1-5
• /
• 2014

This study was carried out to investigate the effect of feeding fermented earthworm cast additives (FEC) on egg production, egg yolk fatty acids, blood lipid, cecal microorganism and fecal odor. The completely randomized experiment was applied, and the treatments were designed as 2 feeding regimens (control vs. FEC feeding), and FEC contained 3.5% top dressing to common diet. Egg production and egg weight of FEC group were significantly higher than that of control (p<0.05). Ratios of n-6/n-3 fatty acids in the egg yolk of FEC group were significantly higher than those in control group (p<0.05). Concentrations of HDL-C in FEC group was significantly higher than control group (p<0.05), but not triglyceride and total cholesterol. The caecal Lactobacillus of FEC group was significantly higher in FEC group than control group (p<0.05). $NH_3$ concentrations from poultry house were significantly lower in FEC group than control (p<0.05). In conclusion, these study results showed that the addition of FEC at 3.5% to the diet has reduced odor of poultry house and improved the n-6/n-3 fatty acid of egg yolk and egg production in laying hens.

• Asian-Australasian Journal of Animal Sciences
• /
• v.12 no.2
• /
• pp.192-196
• /
• 1999

The purpose of this experiment was to study the effects of feeding egg yolk prepared from quail fed winged bean oil on plasma and liver cholesterol and fatty acids composition in rats. Eggs were collected from laying quails that had been fed diets containing 5% of either animal tallow, soybean oil, corn oil or winged bean oil. Yolk powders (referred to as winged bean yolk, soybean yolk, etc.) were prepared and fed at the 15% level to weanling female Wistar rats for 28 days. Rats fed winged bean yolk had significantly lower body weight gain than did rats fed soybean yolk or animal tallow yolk. There are no significant effects on plasma total cholesterol, liver cholesterol and triglyceride concentration due to feeding yolk powder containing different oil. However, LDL-cholesterol increased and HDL-cholesterol decreased in rats fed winged bean yolk. Liver lipid of rats fed with winged bean yolk had a higher linoleic but a lower linolenic content than did those fed animal tallow yolk. However, rats fed with winged bean yolk had a lower linoleic content than did rats fed soybean yolk or corn yolk. In conclusion, winged bean yolk seemed to have had an adverse effect on rats.

• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.11
• /
• pp.1562-1569
• /
• 2004

The objective of this experiment was to determine the effects of n-3 polyunsaturated fatty acids (n-3 PUFAs)-enriched diet supplemented with different levels of $\alpha$-tocopherol on the activities of hepatic lipogenic-related enzymes and the contents of liver and plasma lipid fractions in laying Tsaiya ducks. A total of 180 30-wk-old laying Tsaiya ducks, at the beginning of peak production, were allotted into 6 treatments with 3 replicates each. Ducks were fed one of the 6 experimental diets, containing 4% tallow (control), and 4% fish oil supplemented with graded levels of $\alpha$-tocopheryl acetate ($\alpha$-tocopherol) at 0, 100, 200, 300 and 400 mg/kg, respectively, for 6 wks. Feed and water were supplied ad libitum throughout the experimental period. The results indicated that the n-3 PUFAsenriched diet supplemented with different levels of $\alpha$-tocopherol did not affect (p>0.05) egg weight, feed intake, body weight change or liver and abdominal fat weights. Egg production, egg mass and feed efficiency significantly (p<0.05) improved as dietary $\alpha$-tocopherol levels increased. The activities of hepatic lipogenic-related enzymes including acetyl-CoA carboxylase (EC 6. 2. 1. 3; ACC), glucose-6-phosphate dehydrogenase (EC 1. 1. 1. 49; G-6-PDH), ATP-citrate cleavage enzyme (EC 4. 1. 3. 8; CCE), NADP-malate dehydrogenase (EC 1.1.1.40; NADP-MDH) and fatty acid synthetase (FAS) were higher (p<0.05) in birds fed with the tallow diet than in those fed with fish oil diets and increased with increasing dietary $\alpha$-tocopherol levels. None of the dietary treatments significantly affected the contents of triglyceride and total cholesterol in the liver, or total cholesterol, phospholipid and total lipid in the plasma. However, the contents of phospholipid and total lipid in the liver, and triglyceride in the plasma increased as dietary $\alpha$-tocopherol levels increased. Increasing dietary $\alpha$-tocopherol levels decreased the non-esterified fatty acid (NEFA) content in the plasma and trended to decrease the cholesterol contents in the egg yolk. The lipid metabolism of laying Tsaiya ducks was influenced not only by the dietary fat but also by the supplementation levels of $\alpha$-tocopherol.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.9
• /
• pp.1318-1323
• /
• 2008

Corn distiller's dried grains with solubles (DDGS) is a completely new feed ingredient in the Korean feed market. There is an ever increasing need for the Korean feed industry to import and make the best of it as a high protein and high energy feed ingredient. A layer feeding trial was conducted for 10 weeks to investigate the effects of addition of light-colored DDGS to layer diets on laying performance, egg qualities and yolk fatty acid composition. Also, the economics of using DDGS in the Korean situation was analyzed. Nine hundred Hy-line Brown layers, 24 weeks of age, were employed in a feeding trial consisting of four dietary treatments (0, 10, 15, and 20% DDGS), and five replicates per treatment. All experimental diets were prepared as iso-protein (17%) and iso-calorie (TMEn 2,780 kcal/kg). The use of DDGS up to 20% in layer diets did not exert any influence on feed intake, laying rate, total egg mass, mean egg weight and feed conversion ratio (p>0.05). The color and breaking strength of eggshell, as well as the albumin height and Haugh unit were not affected by the addition of DDGS up to 20% in the diet. The yolk color was significantly increased by DDGS supplementation (p<0.05). As the DDGS level increased, the oleic acid content decreased, and the linoleic acid increased (p<0.05) in egg yolk. The degree of saturation of yolk fatty acids was not affected by DDGS supplementation. The inclusion of light-colored DDGS up to 20% in layer diets resulted in a decrease of feed cost per kg without any undesirable effect on laying performance. In conclusion, the light-colored DDGS (L* 56.65) could be used up to 20% in layer diets without any harmful effect on laying performance, and possibly provide economic benefits to the Korean poultry industry.

• Journal of Sericultural and Entomological Science
• /
• v.8
• /
• pp.35-40
• /
• 1968

As a result of investigating the change of Ascorbic acid and Lipid which have a relation with metabolism of a silkworm egg in the process of the growth of embryo is silkworm eggs. The following facts have been found 1) Ascorbic acid has gradually increased before the period of the Byong B embryo and it has decreased after period of Byong B embryo. 2) Triglyceride and Total cholesterol has gradually increased before the period of the Byong B embryo and it has decreased after period of the Byong B embryo. 3) Phospholipid has gradually decreased before the period of the Byong A embryo and it increased during the Byong B embryo and decreased again at same stage. It has increased from the head pigment of embryo to hachting. 4) Free Fatty acid decreased during the Byong A embryo stage and increased from the Byong B embryo stage to the Ki A embryo stage and decreased again and increased shortly before the hachting.

• Korean journal of applied entomology
• /
• v.34 no.2
• /
• pp.140-146
• /
• 1995

Changes in protein content during oocyte development was measured and egg-specific protein was characterized from the eggs in Lucilia illustris. During normal development ovarian protein was rapidly increased at 72hr and reached maximum at 96hr after a protein meal, when the eggs were fully matured. Purified protein from the ovaries by gel filtration of DEAE-cellulose an Sephacryl S-200 was loaded on 7.5% native polyacrylamide gel electrophoresis and identified at ${R}_{f}$ 0.4 as egg-specific protein, which has a mol. wt of 110,000. A total of 13 amino acids in th egg-specific protein was identified and expecially asparagine, glutamic acid, and tyrosine were highly concentrated. Five fatty acids were also identified. It is suggested that there is a specific protein in the eggs of L. illustris except yolk protein synthesized and secreted by fat body.

• Korean Journal of Poultry Science
• /
• v.20 no.1
• /
• pp.43-54
• /
• 1993

Egg production in Korea was 393 thousand M/T in 1990. More than 10 thousand M/T egg was imported and the amount imported has increased every year. Despite consumption tendency of increasing processed food, creation of additional demand is not likely because domestic egg consumption mainly depends upon table eggs. Processed eggs for marketing in Korea could be classified into two kinds. One is primary processed eggs including liquid eggs and egg powders. The other is secondary processed eggs which are further processed such as egg flake and egg curd. In addition to the above egg products, specific nutrient fortified eggs are produced through the modified feed formula and breeding techniques. The technologies developed so far including Korean patents are introduced. Convenient foods using egg and nutrient controlled eggs will be popular in the near future. For example, low cholesterol egg and polyunsaturated fatty acid fortified egg will be produced to meet the consumer demand. However, facing problems such as introducing egg quality grading systems and extending the short shelf-life of washed eggs should be solved as well.

• Proceedings of the Korea Society of Poultry Science Conference
• /
• 2001.11a
• /
• pp.56-57
• /
• 2001

In Experiment 1, two hundred eighty 32wks old ISA brown layers were assigned to seven dietary treatments for 4weeks. Each treatment was consisted of 4 replications with 10 birds per replication. Control diet was formulated 10%CP 2,750KcalME/kg. Euglena bleached(DHA enriched) at the level of 0.5, 1.0, 2.0% in the diet. In Experiment 2, three hundred 84wks old ISA brown layers were assigned to seven dietary treatments: T1; Control, T2; T1 ＋ Euglena bleached(DHA enriched)0.5%, T3; T1 ＋ Euglena gracilis(DHA enriched)0.5%, T4; T1 ＋ Euglena gracilis(DHA enriched)1.0%, T5; T1＋Euglena gracilis(DHA enriched)2.0%. In Experiment 1, 2.0% Euglena bleached treatment showed highest DHA level in Egg yolk(P＜0.05). In Experiment 2, 0.5% Euglena bleached treatment showed highest DHA level in Egg yolk(P＜0.05).

• Korean Journal of Poultry Science
• /
• v.30 no.3
• /
• pp.183-189
• /
• 2003

This study was carried out to evaluate effect of dietary green tea by-products (GTB) on laying performance and quality of eggs in hens. A total of 96 laying hens (22-week-old) "Tetran Brown" were allotted to four dietary treatments, which containing 0, 2, 4 and 6% green tea-by products. The results showed that the egg production increased (P＜0.05) in layers fed diets containing 4% or 6% green tea-by products compared to the layers fed control no GTB. Egg weight and egg mass in layers fed diets containing 2% green tea by-products significantly decreased compared to those in the other groups (P<0.05). The feed intake was lower in layers fed diets containing 2% and 6% green tea by-products. The feed conversion ratio was lower (P<0.05) in layers fed diets containing 4% or 6% green tea by-product supplementation respectively. The egg shell thickness was no significantly different between layers fed the control and green tea by-product diets (P>0.05). The egg yolk cholesterol tended to decrease when layers fed diets containing green tea by-products, although the differences were not significant (P＞0.05). The linolenic and docosahexaenoic (DHA) acid contents in egg yolk significantly increased in layers fed diets containing different levels green tea by-products compared to those fed control diet (P<0.05). These results suggest that inclusion of green tea by-products in layer diets is suitable for hens without negative effects on egg composition.