• The Korea Journal of Herbology
• /
• v.29 no.5
• /
• pp.31-38
• /
• 2014

Objectives : Egg yolk is composed of various important chemical substances for human health. A calcium shortage causes the growth retardation on the body growth. In this study, we examined the therapeutic effects of calcium, vitamin D and egg yolk peptide (EYP) treatment on the retardation of the longitudinal bone growth induced by low-calcium diet in adolescent rats. Methods : Low calcium diets were administrated for 15 days. During the last five days, calcium and/or vitamin D and/or EYP were administrated. The body weights, longitudinal bone growth rates, the heights of growth plates, and bone morphogenetic protein (BMP)-2 and insulin-like growth factor (IGF)-1 expressions were measured using histochemical analysis. Results : Low calcium diets caused the significant reduction in body weight gains and the longitudinal bone growth. The heights of growth plates and the expressions of BMP-2 and IGF-1 showed the impairment of body growth as well. Calcium and/or vitamin D administration could not significantly increase the longitudinal bone growth. However, calcium, vitamin D, and EYP administration significantly increased the bone growth, the growth plate height, and BMP-2 and IGF-1 expressions. Conclusions : These results suggest that EYP enhances the longitudinal bone growth in the calcium and/or vitamin D deficiency and it could be a promising agent for the treatment of children suffering from malnutrition.

• Korean Journal of Poultry Science
• /
• v.26 no.3
• /
• pp.179-188
• /
• 1999

The present was undertaken to establish a model for the control of adipocytes differentiation by using antibody from egg yolk. The emulsion of membrane protein of 3T3L-1 cell membrane protein with the complete Freund's adjuvant was firstly immunized in layer. Second and third boosting were undertaken with two weeks intervals by injection of the emulsion of the same antigen with the incomplete Freund's adjuvant. After 4 week of the first immunization, eggs were collected and antibody (IgY) was purified from egg yolk. The purity of IgY was 60-98% determined by single radial immunodiffusion (SRID) methods. Titer value of the antibody showed high reactiviy for the preadipocytes membrane protein measured by ELISA. When the IgY was added in the test media containing either 2.5% porcine serum or 10% FBS(control), the differentiation of 3T3L-1 cells and Glycerol-3-phosphate dehydrogenase(GPDH) activities was significantly decreased compared to the control cells(p〈0.05). When mice were subcutaneously injected with IgY raised against membrane protein of 3T3L-1 cells for 3 weeks, adipose tissue mass around ovary was tended to be decreased in female mice compared to those of control mice. It is suggested that a potential for manipulating of lipid accumulation through decrease in 3T3L-1 cell differentiation and fat accumulation in female mice by IgY treatment.

• Journal of Photoscience
• /
• v.9 no.2
• /
• pp.261-263
• /
• 2002

The presence of retinals (retinal and 3,4-didehydroretinal) has been known in the eggs of wide range of oviparous vertebrates, but the biological significance of the egg retinals has yet to be clarified. We here show that retinals are the major components of retinoids in the eggs of all species of chordate animals we examined. The egg retinals were commonly bound to egg yolk proteins, the storage proteins, via a Schiff base linkage. The Schiff base linkage, which protects the reactive aldehyde group, would negate the toxicity of aldehyde, and enable to accumulate much amount of retinals. The retinals in chordate eggs are considered to be the precursor of functional retinoids, such as photoreceptive pigment chromophores and retinoic acid, during development. The results of the present research strongly suggest that retinals in the eggs of oviparous chordates are the common and essential mode of retinoid storage.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.11
• /
• pp.1617-1621
• /
• 2002

Two hundred and sixteen single comb white egg layers of the White Leghorn hens of 24 weeks of age were randomly allocated to 12 groups with three replications of six hens in each. Hens were fed in a factorial arrangement 2${\times}3{\times}$2, on diets containing either 16 or 18% crude protein with 0, 3 or 6% fish meal, replacing groundnut meal with soybean meal. Soybean meal incorporation improved (p<0.05) egg production, feed intake, feed conversion efficiency and egg weights. Egg quality traits of specific gravity, shape index, albumen index, yolk index and shell thickness remained unchanged. Laying performance was significantly (p<0.05) better at 18% than on 16% dietary protein level. Use of fish meal linearly improved egg production and feed conversion efficiency on diets supplemented with groundnut meal and fish meal incorporation showed quadratic improvement on feed conversion efficiency with SBM diets at 16% dietary protein level. Therefore, use of soybean meal as substitute of groundnut meal is recommended in layer diets, at 16% dietary protein level and fish meal incorporation could be beneficial for layers.

• KSBB Journal
• /
• v.14 no.6
• /
• pp.677-681
• /
• 1999

Purificationi of egg yolk immunoglobulin(IgY) was performed to understand the property of egg immunoglobulin. IgY differs from mammalian IgY in the molecular size(larger), isoelectric point(more acidic), and binding ability with mammalian complement and protein A(nonbinding ability). IgY is also known as ${\gamma}$-livetin and exists in egg yolk together with other two water-solubel proteins, ${\alpha}$-livetin(chicken serum albumin) and ${\beta}$-livetin(${\alpha}_2$-glycoprotein) and various lipoproteins(Low density lipoprotein, LDL and High density lipoprotein, HDL) which are the major components of egg yolk. The first step of isolation of IgY is to separate the water-solube proteins from lipoproteins. We report a simple method for separation of water soluble proteins using k-carrageenan and sedimentation. k-carrageenan was found to be effective for removal of yolk lipoprotein as a precipitate. IgY remained supernatant, and was isolated by chromatography on columns of DEAE-Sephacel and G 75 gel filtration chromatography.

• Korean Journal of Poultry Science
• /
• v.21 no.2
• /
• pp.139-150
• /
• 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.

• Journal of Nutrition and Health
• /
• v.47 no.6
• /
• pp.385-393
• /
• 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.

• Journal of Aquaculture
• /
• v.9 no.1
• /
• pp.83-92
• /
• 1996

This study was conducted to compare the immunochemical properties of female-specific serum proteins (vitellogenin, VTG) and egg yolk proteins in female fusilier, Caesio diagramma. VTG of fusilier was identified and characterized by using immunochemical analysis. Two types of VTG (VTG1 and VTG2) reacted clearly with antiserum against egg proteins, were confirmed in the serum of mature female. The results of sephacryl S-300 showed that the molecular weights of VTG1 and VTG2 were 560,000 and 410,000, respectively. Yolk proteins, E2 and E3, were isolated from egg extracts, and molecular weights of them were estimated 410,000 and 170,000, respectively. The treatment of $17\beta$-estradiol ($E_2$) to males has induced the synthesis of VTG of which immunological characteristics seems to be similar to the yolk proteins. The results suggest that VTG can be synthesized in the liver by the action of $E_2$ stimulation, and incorporated into the oocytes through the blood circulation. The level of serum $E_2$ was moderately high throughout the spawning period of June. The level of serum VTG was also sustained at high in May and June. The concentration changes of serum $E_2$ and VTG were corelated to the ovarian development in female fusilier. The results indicated that $E_2$ may have some important roles for the vitellogenesis in female fusilier. Also) the VTG can be a precursor protein of yolk not only because it could be synthesized in the liver then incorporated into the oocytes but also because an egg yolk protein had the similiar molecular weights and antigenecity with VTG.

• Asian-Australasian Journal of Animal Sciences
• /
• v.28 no.11
• /
• pp.1641-1648
• /
• 2015

This study was conducted to evaluate the effects of various protein sources (soybean meal, SBM; cottonseed protein, CSP; double-zero rapeseed meal, DRM) on the internal quality of refrigerated eggs. A total of 360 laying hens (32 wk of age) were randomly allotted to six treatment groups (five replicates per treatment) and fed diets containing SBM, CSP, or DRM individually or in combination with equal crude protein content (SBM-CSP, SBM-DRM, and CSP-DRM) as the protein ingredient(s). A $6{\times}3$ factorial arrangement was employed with dietary types and storage time (0 d, 2 wk, and 4 wk) as the main effects. After 12 wk of diet feeding, a total of 270 eggs were collected for egg quality determination. The egg Haugh unit (HU) in the CSP, SBM-DRM, and DRM groups were significantly lower than those in the SBM and SBM-CSP groups. The hardness and springiness of the cooked yolk in the CSP group were significantly higher than those in the other treatment groups. A lower HU, lower yolk index and higher albumen pH were observed in the DRM group compared to the SBM and SBM-CSP groups when the eggs were stored to 4 wk, and the HU was improved in the CSP-DRM group compared to the DRM group (p<0.05). Higher yolk hardness was observed in the CSP group compared to the other groups during storage (p<0.05), but the hardness of the cooked yolk in the SBM-CSP and CSP-DRM groups showed no difference in comparison to the SBM group. In conclusion, CSP may ameliorate the negative effects of DRM on the HU of refrigerated eggs, and SBM or DRM may alleviate the adverse effects of CSP on yolk hardness.

• Korean Journal of Poultry Science
• /
• v.40 no.4
• /
• pp.361-368
• /
• 2013

This experiment was conducted to determine optimum levels of dietary crude protein for productivity and egg quality in laying hens during early stage. A total of seven hundred and twenty 24-wk-old Hy-Line Variety Brown layers were randomly assigned to 4 experimental diets varying with 16%, 17%, 18%, and 19% CP and fed the diets for 12 wks. There were no significant differences in egg production, daily egg mass and feed intake among experimental diets. Although no difference was found on egg weight among experimental diets, decreasing levels of dietary crude protein tended to reduce the egg weight. Haugh unit and egg shell quality were not affected by different levels of dietary crude protein. Although there was no difference on yolk color among experimental diets, increasing levels of dietary crude protein slightly reduced the yolk color. It is concluded that laying hens did not need more than 16% CP to maximize egg production.