• Preventive Nutrition and Food Science
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• v.8 no.3
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• pp.294-300
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• 2003

The chicken egg provides a perfectly packaged, portion controlled, highly nutritious food containing vital nutrients essential for maintaining human health. However, concern by health professionals over the possible association of diets high in fat and cholesterol to chronic diseases has led to a decrease in egg consumption. Several different strategies have been adopted by the poultry food industry to enhance the nutritional value of eggs. The major emphasis has been focused on the modification of polyunsaturated fatty acid composition and fat soluble vitamins. This review briefly describes the composition, lipid nutrient content and the positive health effects of egg lipid nutrients.

• Korean journal of food and cookery science
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• v.15 no.6
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• pp.645-651
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• 1999

The lipid and fatty acid composition of various poultry eggs were examined after extracting yolk oils from the eggs of caged hen, open barn-reared hen, mallard, and muscovy duck. Total lipid content in 100 g of each edible portion was the highest in muscovy duck egg followed by open barn-reared hen, mallard, caged hen, and natural hen eggs. The triglyceride contents in the egg were in the order of caged hen, open barn-reared hen, natural hen, mallard, and muscovy duck. The cholesterol contents in total lipid were the highest in caged hen and muscovy duck eggs(4.5%), and the lowest in mallard(3.3%). Caged hen eggs had higher neutral lipid ratio among total lipid, but had lower ratio of glycolipid and phospholipid compared with those of the open barn-reared hens. For fatty acid composition, linoleic acid was the highest in the muscovy and linolenic acid was the highest in open barn-reared hen eggs. The contents of arachidonic acid and Eicosapentaenoic acid(EPA) were the highest in muscovy eggs. On the other hand, the content of Docosahexaenoic acid(DHA) was the highest in muscovy duck eggs.

• Journal of Environmental Science International
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• v.27 no.5
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• pp.341-344
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• 2018

This study was conducted to determine the effects of dietary bentonite supplementation on the fatty acid profiles of eggs in older laying hens. A total of 90 Hy-line Brown layers, 74 weeks of age, were confined in 6 wire cages and then assigned randomly to two groups to receive one of the two diets (3 replicates of 15 older layers each) containing 0 and 0.2% bentonite for 4 weeks. After the 4-week feeding trial, no remarkable differences in individual fatty acid, saturated fatty acid (SFA), unsaturated fatty acid (UFA), and mono unsaturated fatty acid (MUFA) levels were found. However, linoleic acid, docosahexaenoic acid, and poly unsaturated fatty acid (PUFA) and UFA/SFA ratio were influenced by 0.2% bentonite. In conclusion, supplementation with 0.2% bentonite improved the profiles of PUFA more than those of SFA, UFA, and MUFA inthe eggs of the older laying hens.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.4
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• pp.565-569
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• 2003

The objective of this experiment was to determine the effects of different levels of refined cod liver oil (RCLO) on laying performance, n-3 polyunsaturated fatty acids composition (n-3 PUFAs) and the organoleptic evaluation of duck egg yolks. 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, supplemented with 2% tallow (control) and graded levels of RCLO at 2, 3, 4, 5, and 6% to a corn-soybean diets, respectively, for 6 wks. All of the experimental diets were formulated to be both isocaloric and isonitrogenous. Feed and water were supplied ad libitum throughout the experimental period. The results indicated that the RCLO supplementation levels did not affect (p>0.05) egg production, egg mass, feed intake, feed efficiency or body weight change. Egg weight was the lightest when the ducks received the 6% RCLO diet. The eicosapentaenoic acid, docosahexaenoic acid, and total n-3 PUFAs contents in the yolks increased with increasing RCLO supplementation. The taste and general acceptability of the hard-boiled eggs were not significantly different among the treatments. However, a fishy flavor was much higher when ducks were fed diets supplemented with 5% and 6% RCLO diets.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.7
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• pp.1047-1053
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• 2006

The current study was designed to determine the effects of dietary docosahexaenoic acid (DHA) on fatty acid deposition in egg yolk and various tissues of laying Tsaiya ducks, and on the mRNA concentrations of hepatic lipogenesis-related transcription factors. Thirty laying ducks were randomly assigned to three treatments with diets based on corn-soybean meal (ME: 2803 kcal/kg; CP: 17.1%; Ca: 3.4%) supplemented with 0% (control diet), 0.5% or 2% algal DHA oil. The DHA content in egg yolks of the ducks was elevated significantly (p<0.01) with the supplementation of dietary DHA. The DHA percentage of the total fatty acids in the egg yolk of laying ducks was 0.5%, 1.3% and 3.4% for 0%, 0.5% and 2% algal DHA oil treatments, respectively, for the $1^{st}$ week, and 0.5%, 1.5% and 3.3% for the $2^{nd}$ week. Therefore, algal DHA oil can be utilized by laying Tsaiya ducks to enhance the egg-yolk DHA content. The concentrations of triacylglycerol (TG) and cholesterol in plasma of laying Tsaiya ducks were not affected by dietary DHA treatments (p>0.05). The DHA concentration in plasma, liver, and skeletal muscle was increased with the addition of dietary algal DHA oil (p<0.05). The mRNA abundance of sterol regulatory element binding protein 1 (SREBP1) and SREBP2 in the livers of laying Tsaiya ducks was not affected by dietary DHA, suggesting that the expression of these transcription factors is tightly controlled and not sensitive to DHA treatments.

• Animal Bioscience
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• v.35 no.2
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• pp.236-246
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• 2022

Objective: The objective of this study was to investigate the effect of dietary pumpkin (Cucurbita moschata) seed meal (PSM) on laying hens' performance, quality, fatty acids, cholesterol, antioxidant compounds and shelf life of eggs. Methods: Eighty Tetra SL laying hens, 50-week-old, were randomly divided into two equal groups, having 10 replicates with 4 birds in each. The control (CON) treatment was fed with basal diet, while experimental treatment was fed a diet with 9% PSM, for a 6 week period. Results: Dietary PSM significantly decreased average daily feed intake (p<0.05), with no significant effect on other performance parameters. The PSM, enriched the eggs with polyunsaturated fatty acids, especially α linolenic acid (0.33 vs 0.21 g/100 g) and linoleic acid (20.65 vs 18.37 g/100 g), whereas it reduced the amount of arachidonic acid with 3.91% and n-6/n-3 ratio in PSM eggs compared with CON. The inclusion of 9% PSM significantly (p<0.05) diminished the cholesterol concentration in yolk with 11.31% and in egg with 10.38%, in respect to the CON samples. The significantly (p<0.05) higher concentration of polyphenols and antioxidant compounds, determined in PSM eggs, proved to be effective on shelf life of eggs preserved at refrigerator (5℃) and room temperature (21℃) for 28 days, by delaying the lipid oxidation and protein denaturation. This effect was reflected in significantly (p<0.05) higher Haugh unit in eggs stored 28 days at 21℃ and lower albumen pH values for the overall storage time, both at 5℃ and 21℃, proving the antioxidant effect of pumpkin. Conclusion: Dietary PSM supplementation was significantly effective on average daily feed intake and egg quality by increasing some fatty acids while lowering the cholesterol concentration. Also, PSM proved to be effective improving shelf life of eggs for 28 days storage time.

• Korean Journal of Poultry Science
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• v.26 no.4
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• pp.217-236
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• 1999

Among polyunsaturated fatty acids (PURAs) targeted for manipulation in animal tissues (poultry eggs and meat), omega-3 PUFAs(n-3 PUFAs) are discussed in this review. 3 or 5% dietary menhaden oil (MO) supplemented layer diets was reported to increase docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) contents in the egg. MO at 1.5% also increased the deposition of up to 180mg total omega-3 fatty acids / yolk. Utilization of 5% ground flax seed (FS) resulted in similar total omega-3 fatty acid (FA) deposition as 1.5% MO. However, the basic feed formulations used in the Canadian feed industry usually include 10 to 20% FS in the egg laying diets. Recently several studies reported that addition of tocopherols in layer diets increased the tocopherol content more in the egg than any other tissue. One of reports said that 3.5% dietary oil with added tocopherols resulted in increasing tocopherol deposition and FA composition of the egg and other tissues. In the poultry meat, redfish meal (RM;4, 8, 12, 15 and 30% of diet) or redfish oil (RO;2.1 or 4.2% of diet) added to the practical corn-wheat-soybean based diets resulted in an increase in omega-3 FA and docosapentaenoic acid (DPA) contents in broiler meat lipids. Linseed oil (LO;1.0, 2.5, and 5.0% of broiler diet) supplemented in broiler diets also resulted in omega-3 FA and the ratio of omega-6 being significantly higher in poultry meat lipid than MO. Concern about fish flavor resulted in research about fish oil (FO) supplementation in broiler diets. Without the use of antioxidants, no more than 1.5% FO should be fed to broilers due to unacceptable orders from the chicken carcasses. One recent research project found that over 50mg/kg of vitamin E was required for maintaining the stability of unsaturated lipids in the meat. In regards to 'fishy'or 'crabby'taint in the eggs and poultry meat, poultry products remained acceptable when dietary fish oils were stabilized with antioxidants.

• Korean Journal of Poultry Science
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• v.32 no.3
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• pp.203-209
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• 2005

This study was conducted to evaluate the ffeding value of dried fly larva (DFL), and the effects of dietary DFL on the performance of laying hens. Ninety laying hens of 43 weeks of age(ISA brown) were randomly allotted to 5dietary treatments (0, 2, 5, 10 and $15\%$ DFL), and fed one of the experimental diets for 8 weeks. The formulae of 5 experimental diets were modified to contain $18.8\%$ CP and 2,900 ME kcal/kg. There were 3 replicates per treatment, and 6 brids Per replicate. No significant difference was found in egg Production among dietary treatments. The egg weight was increased (p<0.05) in DFL treatments compared to the control. Also, the egg shell breaking strength was increased(p<0.05) in DFL treatments by $14\%$ compared to the control. The saturated fatty acid content in egg yolk was decreased by $16\%$, and that of unsaturated fatty acid increased by $7\%$ in DFL treatments. Therefore, it could be suggested that DFL supplementation could improve the egg Qualify by increasing the egg weight, egg shell strength, and unsaturated fatty acid content in egg yolk.