• 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.

• The Korean Journal of Food And Nutrition
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• v.17 no.2
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• pp.206-211
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• 2004

It is very important to minimize the acid value of oil in the oil and fat industry, because acid value of oil products are a indicator quality. This study was performed to investigate change of moisture content, acid value and free fatty acid content by drying condition such as drying method, temperature and drying time on steamed duck egg york. Also, change of fatty acid composition by acid value. The acid values, moisture contents and free fatty acid contents were showed comparatively lower value by spray drying and freeze drying than by steam drying. but difference that keep in mind between each drying method was not looked. Whereas moisture content, acid value and free fatty acid content of effect of drying temperature reaches in lowest value. also, did not show change until dry 12hours reaching to lowest value by 3.1, 3.0％ and 0.98％ after dry 9hours both moisture content, acid value and free fatty acid content. Also, acid value increase, free fatty acid was increased, where unsaturated fatty acid showed that decrease rapidly.

• Korean Journal of Poultry Science
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• v.32 no.4
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• pp.261-268
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• 2005

The purpose of this study was to evaluate the effect of dietary ceramic powder on laying performance, Pathogenic bacterial (E. coli, salmonella) counts in caecal contents and excreta, malodorous substances $(NH_3,\;H_2S,\;VFA)$ in excreta and fatty acid composition of e99 yolk in laying hens. Three hundred sixty layers at 34 weeks of age were divided into three groups of 120 hens each and each group was fed diets containing 0 (control), 0.4, or 0.8 ceramic powder for six weeks. It is concluded that $0.4\%$ ceramic powder supplementation of diets decreased of E. coli, salmonella counts in the intestine and emission of $NH_3$ and VFA gas from excreta, and improved the laying Performance and ratio of egg yolk fatty acids contents.

• Proceedings of the Korean Nutrition Society Conference
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• 2001.05a
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• pp.237.1-237
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• 2001

• Korean Journal of Poultry Science
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• v.30 no.3
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• pp.161-167
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• 2003

A study was conducted to investigate the effect of supplementing earthworm meal (EWM) on the performance of laying hens and fatty acid composition in egg yolks. A total of 360 laying hens at 55 weeks of age were fed the experimental diets containing 0.0% (Control), 0.1% and 0.2% of EWM for 5 weeks. Eggs were collected and weighted every day and egg production and feed conversion were recorded every weeks during the experimental period. However fatty acid composition of egg yolk were measured at last week of experimental period. Amount of feed intake tended to increase by supplemental EMW, but feed conversion ratio of birds fed EWM was not different among three groups. Average egg production seemed to increase and significantly improved (P<0.05) when fed a 0.1% EWM and 0.2% EWM, respectively. Average egg weight was prone to decrease when fed a 0.1% EWM compared to that fed a 0% (control) or 0.2% EWM. Average daily egg mass tended to improve by the addition of EWM. It was more increased in 0.2% EWM treatment than 0.1% EWM. The ratio of egg yolk n-6/ n-3 fatty acids contents was 5:1 fed a 0.1% and 0.2% EWM. But these ratio was 10:1 in control group. It is concluded that 0.2% earthworm meal supplementation in the 55 weeks old laying hens diet, improves the laying performance and ratio of egg yolk n-6/ n-3 fatty acids contents (P<0.05).

• Korean journal of food and cookery science
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• v.13 no.2
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• pp.87-91
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• 1997

Egg yolk oil was obtained by roasting and Pressing egg yolks of hen's egg breeding on the open bin system and the cage system, respectively. Lipids in egg yolk oil were extracted with a mixture of chloroform and methanol (2 : 1, V/V), and fractionated into neutral lipid, glycolipid, and phospholipid by silicic aicd column chromatography. Fatty acid composition of each fraction was determined by gas chromatography. The major fatty acids of total lipids and neutral lipids are in sequence of oleic acid, palmitic acid, and linoleic acid. The major fatty acids of the glycolipids are palmitic acid, oleic acid, stearic acid, and lauric acid successively. The major fatty acids of phospholipids are oleic acid, lauric acid, and Palmitic acid consecutively. About the fatty acids composition of egg yolk oil in the open barn system, the contents of saturated fatty acid are lower and the contents of unsaturated fatty acid are higher than that of the case system. The contents of unsaturated fatty acid in egg yolk oil is higher than that of saturated fatty acid in total lipids and nutral lipids. Unsaturated fatty acid/saturated fatty acid of e99 yolk oil in the open barn system is higher than that of the cage system in glycolipids and phospholipids.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 1996.06a
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• pp.29-29
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• 1996

• Korean Journal of Poultry Science
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• v.31 no.4
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• pp.283-291
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• 2004

Feeding trials were conducted with Euglena strains grown under different media. The effect of supplementation of Euglena on the laying performance, egg quality and fatty acid composition of egg yolk was studied. In experiment I, two hundred eighty 32-wk-old ISA Brown layers were randomly assigned to seven dietary treatments for 4 wks. Each treatment consisted of 4 replications with 10 birds each housed in two birds cages. Control diet was formulated to have $17\%$ CP and 2,750 kcal ME/kg. Euglena gracilis Z. (EG) was added to control diet at the level of 0.25, 0.5, $1.0\%$ and Euglena gracilis Z. bleached and DHA enriched (EGBD; a strain mutated by streptomycin and cultivated in DHA enriched medium) at the level of 0.5, 1.0, $2.0\%$ in the diet. In experiment 2, three hundred 84-wk-old ISA brown layers were randomly assigned to five dietary treatments: T1; Control, T2; T1 + EGBD $0.5\%$, T3; T1 + Euglena gracilis Z. DHA enriched (EGD; cultivated in DHA enriched medium) $0.5\%$, T4; T1 + EGD $1.0\%$, T5; T1 + EGD $2.0\%$. Each treatment had 5 replication of 12 birds each housed in two birds cages. In experiments 1 and 2, Euglena suppplementation did not significantly affect egg production but increased egg weight and feed intake. In experiment 1, EG was more effective in increasing egg yolk color score than EGBD. Egg yolk color of EG $1\%$ treatment showed the highest score. EGBD supplementation increased DHA concentration of egg yolk. EGBD $2\%$ treatment showed the highest DHA and the lowest palmitic and stearic acids concentration in the egg yolk. In experiment 2, EGBD $0.5\%$ treatment showed highest DHA level in egg yolk (P<0.05). It was conducted that EGBD is a single cell protein source rich in DHA, that can be used to produce DHA enriched eggs.

• Korean Journal of Poultry Science
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• v.32 no.1
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• pp.35-41
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• 2005

The objectives of the present study were to investigate the effects of varying levels of dietary oil containing conjugated linoleic acid (CLA) on the egg production and fatty acid composition of egg yolk. Seventy-two 59-wk-old ISA Brown laying hens were randomly allotted to four dietary treatments, each consisting of three replicates with six birds per replicate. There were four treatments that consist of diets containing 0, 1, 2, or $3\%$ commercial CLA-containing oil. Egg production was not significantly different among the dietary treatments at 0, 2, 4, and 6 week. The proportion of saturated fatty acids such as C16:0 and C18:0 in egg yolk were increased, but that of monounsaturated fatty acid C18:1 was decreased by feeding CLA-containing oil supplementation. However, the proportion of polyunsaturated fatty acids such as C18:2 and C18:3 in egg yolk were not different among dietary treatments at 2 and 4 wk of the experiment. At 6 week, the proportion of C18:2 in egg yolk was decreased by feeding CLA-containing oil compared with the control. Polyunsaturated fatty acid:saturated fatty acid (P:S) ratio and n-6:n-3 polyunsaturated fatty acid ratio were similar across the treatments between 2 and 4 week. The P:S ratio was decreased by dietary CLA-containing oil supplementation at 6 week. The proportion of CLA in egg yolk was linearly increased with increasing levels of CLA-containing oil supplementation. In conclusion, dietary supplementation of CLA-containing oil to laying hens increased beneficially increased CLA content in their egg yolk.

• Journal of Life Science
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• v.20 no.9
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• pp.1358-1364
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• 2010

In this study, the effects of feeding citrus by-products on the quality and fatty acid compositions of chicken eggs were investigated. Two samples of chicken eggs were used for this study: T0 (eggs of chickens that were not fed citrus byproducts) and T1 (eggs of chickens that were fed 4% citrus byproducts). There was no statistically meaningful difference between T0 and T1 in terms of various properties, such as chemical composition, cholesterol content, minerals, vitamins, pigments, and total structural amino acid. The caloric content of the egg yolk was higher in T1 than in T0, and total free amino acid of egg albumin and egg yolk was higher in T1 than in T0 (p<0.05). There was a not significant difference in SFA:UFA ratio between T0 and T1, but the linolenic acid content was higher in T1 than in T0 (p<0.05). The results of this study show that citrus by-products can be used for feed for laying hens by adding them to general feed.