Characterization of the n-3 polyunsaturated fatty acid enrichment in laying hens fed an extruded flax enrichment source

Egg production, egg quality, and fatty acids profiles in eggs and tissues in Lohmann LSL lite hens fed algal oils rich in docosahexaenoic acid (DHA)

Enriching eggs with omega-3 fatty acids (n-3 FA), such as docosahexaenoic acid (DHA), is a well-accepted practice that benefits the egg industry and consumers. However, issues around cost, sustainability, and product acceptance have necessitated the search for alternatives to feeding hens fish oil for DHA enrichment. The effects of feeding 2 algal oils on egg production and DHA enrichment in eggs and selected tissues were investigated. The algal oils were: 1) OmegaPro (OPAO) standardized algal oil for DHA content and 2) Crude algal oil (CAO). A total of 400, 46-wk-old Lohmann LSL lite hens were housed in enriched cages (10 birds/cage) and allocated 5 diets (n = 8) for a 12-wk trial. The iso-caloric and -nitrogenous diets were a standard corn and soybean meal diet, standard plus 0.25 or 0.76% OPAO and standard plus 0.23 or 0.69% CAO; algal oils diets supplied similar DHA at each level. Egg production indices (hen day egg production, feed intake, FCR, egg weight, egg mass, and eggshell quality) were monitored for 10 wk. Diet samples were analyzed for fatty acids (FA) on wk 1, 6, and 12 and eggs on wk 4, 5, 6, 9, and 12. At the end of the trial, one hen/cage was weighed and dissected for liver, breast and thigh for FA and long bones for ash content analyses. Concentration of omega-6 to omega-3 FA ratio was 12.9, 6.64, 3.48, 6.96, and 3.59 for standard, 0.23 and 0.76% OPAO, 0.25 and 0.69% CAO, respectively. Algal oils increased (P ≤ 0.046) eggshell thickness linearly. The concentration of DHA in the eggs from the birds fed the standard, 0.23 and 0.76% OPAO, 0.25 and 0.69% CAO was 84, 195, 286, 183, and 297 mg/100g egg, respectively, and algal oils enriched eggs with DHA linearly and quadratically (P ≤ 0.01). In conclusion, algal oils increased the concentration of DHA in eggs and had no adverse effects on egg production and eggshell quality.

A review of recent studies on the enrichment of eggs and poultry meat with omega-3 polyunsaturated fatty acids: novel findings and unanswered questions

Studies from our laboratory over the past decade have yielded new information with regard to the dietary enrichment of eggs and poultry meat with omega-3 (n-3) polyunsaturated fatty acids (PUFA) but have also generated a number of unanswered questions. In this review, we summarize the novel findings from this work, identify knowledge gaps, and offer possible explanations for some perplexing observations. Specifically discussed are: 1) Why feeding laying hens and broilers an oil rich in stearidonic acid (SDA; 18:4 n-3), which theoretically bypasses the putative rate-limiting step in the hepatic n-3 PUFA biosynthetic pathway, does not enrich egg yolks and tissues with very long-chain (VLC; ≥20 C) n-3 PUFA to the same degree as obtained by feeding birds oils rich in preformed VLC n-3 PUFA; 2) Why in hens fed an SDA-rich oil, SDA fails to accumulate in egg yolk but is readily incorporated into adipose tissue; 3) How oils rich in oleic acid (OA; 18:1 n-9), when co-fed with various sources of n-3 PUFA, attenuates egg and tissue n-3 PUFA contents or rescues egg production when co-fed with a level of docosahexaenoic acid (DHA; 22:6 n-3) that causes severe hypotriglyceridemia; and 4) Why the efficiency of VLC n-3 PUFA deposition into eggs and poultry meat is inversely related to the dietary content of α-linolenic acid (ALA; 18:3 n-3), SDA, or DHA.

Supplementary n-3 fatty acids sources on performance and formation of omega-3 in egg of laying hens: a meta-analysis

A meta-analysis was performed to evaluate the effects of supplementary n-3 polyunsaturated fatty acids (PUFA) sources in the diet on the formation of some important n-3 PUFA contents in eggs and to assess factors contributing to the conversion efficiency of omega-3 in laying hens. A dataset was constructed from 34 studies examining the impact of dietary inclusion with ingredients rich in n-3 PUFA on fatty acids profile and production performance of laying hens. The eligibility criteria were developed to obtain studies reporting required information with sufficient quality. The mixed model methodology was employed where the “study” was set as random effects and fatty acid (FA) supplements as fixed effects. Several factors were included in the models as covariates. Discrete analysis for sources of FA was also performed to compare their effects on FA formation in eggs. Significant linear positive associations were observed between the concentration of α-linolenic acid (ALA), total n-3 PUFA, and the ratio of linoleic acid (LA) to ALA (LA/ALA) in diets with the formation of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), total n-3 PUFA, and n6/n3 ratio in egg (P < 0.05) with different magnitudes. ALA and total n-3 PUFAs concentration had no relationship with cholesterol concentration, feed intake, and egg weight. Prediction models for DHA formation was higher for ALA as predictor variables (slope = 0.482; R² = 0.684) than n-3 PUFAs (slopes = 0.998, R² = 0.628). Significant interactions were found on the level of ALA × FA sources and n-3 PUFA × FA sources. Fish oil (P = 0.0148, R² = 0.732) improved the prediction equation to estimate DHA formation. To conclude, levels of ALA, n-3 PUFA, and the ratio of LA/ALA can be used as predictor variables to estimate the formation of n-3 fatty acids in eggs. It was confirmed that although all n-3 FA sources had a positive correlation on DHA and n-3 PUFA deposition, however, fish oil showed the highest prediction model for DHA formation across all FA sources included in the dataset.

Omega-3 Fatty Acid Fortification of Flax Through Nutri-Priming

Omega-3 (n-3) fatty acids (FA) play an essential role in human physiology and health. As a result, a variety of n-3 FA-fortified functional foods have become commercially available for human consumption. These fortified functional foods are created through various processes; however, nutri-priming, a potentially promising fortification approach, has not been utilized to develop plant-based n-3 fortified foods. We sought to determine whether nutri-priming is a viable option to enrich seeds and sprouts with n-3 FA. Additionally, we assessed whether n-3 FA nutri-priming would inhibit germination of the primed seeds. To address these goals, we nutri-primed brown flax in three priming solutions, control [0% fish oil (FO)], 10% FO and a 20% FO solution, and determined the FA content and profile of seeds and sprouts and germination percentage of primed seeds. n-3 FA nutri-priming with FO altered the FA profile in seeds and sprouts, with increases in the absolute content of 20:5 n-3, 22:6 n-3, 22:5 n3, 18:4 n-3, and 20:4 n-6. However, n-3 FA nutri-priming did not increase the absolute content of 18:2 n-6, 18:3 n-3, total saturated FA, total monounsaturated FA, total polyunsaturated FA, total n-6 FA, or total n-3 FA. Our results also showed that n-3 nutri-priming decreased the germination percentage of primed seeds, with 10 and 20% FO priming solution reducing germination by 4.3 and 6.2%, respectively. Collectively, n-3 nutri-priming modified the n-3 FA profile in flax; however, the process does not increase the total n-3 FA content and inhibits germination of primed seeds. Further research utilizing different seed types, oil types, and oil concentrations needs to be conducted to fully determine if n-3 nutri-priming is a commercially viable approach for n-3 fortification of seeds and sprouts.

Laying Performance, Egg Quality Characteristics, and Egg Yolk Fatty Acids Profile in Layer Hens Housed with Free Access to Chicory- and/or White Clover-Vegetated or Non-Vegetated Areas

Simple Summary

Outdoor-based systems can improve the product quantity and quality in laying hens. This study investigated the laying performance and several egg quality characteristics in layer hens fed on a conventional diet with free access to a soil area (control, C), a chicory (CI)- or white clover (TR)-vegetated area, or a CI and TR mixture (MIX)-vegetated area. The C hens consumed more concentrate feed, without affecting the laying rate, than did TR and MIX hens. Herbage intake (HI) of the TR and MIX hens was higher than that of the CI birds. The C hens produced eggs with thicker shells than the CI, TR, and MIX hens. The decrease in the feed intake and the improvement in fatty acid (FA) profiles of the egg yolk was related to the HI. Concerning the TR and MIX vegetation, the FA composition of herbage contributed to the production of eggs with preferred FA attributes, such as polyunsaturated FAs and a favourable n-6 to n-3 ratio.

Abstract

This study investigated the laying performance, egg quality, and egg yolk fatty acids (FAs) and cholesterol content in layer hens housed with free access to chicory- and/or white clover-vegetated areas. During a 16-week study, 400 Lohmann Brown hens (32 weeks old) housed with free outdoor access were allocated randomly into four groups, each with four replicates of 25 hens. Control hens were fed a conventional diet with free access to a soil area (C), whereas other hens were fed on a conventional diet with free access to a chicory (CI)- or white clover (TR)-vegetated area or a CI and TR mixture (MIX)-vegetated area. The C hens consumed more concentrate feed (p = 0.018) than the TR and MIX hens, which had a higher herbage intake than the CI birds (p < 0.001). The C hens produced eggs with a thicker shell than those in the other treatment groups (p = 0.013). Compared with C, the saturated FAs of egg yolk decreased for MIX (p = 0.010). The polyunsaturated FAs were higher in the MIX eggs than in the C and TR eggs (p < 0.001). Although FAs were distributed in all quadrants of the principal component analysis (PCA), three main FA profiles could be identified based on the loadings of natural groupings in the PC2 versus PC1 plot. The present study shows clear evidence for the contribution of herbage to the hen diet without affecting laying performance. In addition, the FA composition of the CI and MIX vegetation contributed to the production of eggs with preferred FA attributes, such as polyunsaturated FAs and a favourable n-6 to n-3 ratio.

Effects of feeding ISA brown and Shaver white layer breeders with sources of n-3 fatty acids on hatching egg profiles, apparent embryonic uptake of egg components, and body composition of day-old chicks

Effects of feeding ISA brown and Shaver white breeders sources of n-3 fatty acids (FA) on egg components, apparent embryonic uptake (AEU) of egg components, and hatching body composition were examined. A total of 240 females and 30 males per each strain were fed either: (1) control (CON); (2) CON + 1% of dried microalgae (DMA), as a source of docosahexaenoic acid; or (3) CON + 2.60% of dry extruded product consisting of full-fat flaxseed (FFF), as a source of α-linolenic acid for 30 d. Eggs were incubated and the residual yolks (RY) sampled at hatch for AEU of dry matter (DM), minerals, and organic matter (OM). Feeding n-3 FA sources reduced the AEU of OM and minerals resulting in a higher ratio of RY to body weight (P = 0.002). Feeding FFF increased body fat and decreased lean in Shaver white hatchlings compared with CON (P < 0.05). The body mineral was reduced by feeding DMA compared with other treatments (P < 0.05). The change in body composition in response to feeding of n-3 sources was associated with the change in AEU of DM, OM, and minerals, not the concentration of these components in the yolk.

Impact of feeding n-3 fatty acids to layer breeders and their offspring on concentration of antibody titres against infectious bronchitis, and Newcastle diseases and plasma fatty acids in the offspring

1. The impact of feeding sources of n-3 fatty acids (FA) to ISA Brown and Shaver White breeders and their offspring on antibody titres and plasma FA profile was examined.2. Breeders were fed either a control diet (CON); CON + 1% microalgae (DMA: Aurantiochytrium limacinum) as a source of docosahexaenoic acid; or CON + 2.6% of a co-extruded mixture of full-fat flaxseed (FFF) as a source of α-linolenic acid. Day-old female offspring were assigned to diets (breeder-offspring): 1) CON-CON, 2) CON-DMA, 3) CON - FFF, 4) DMA - CON, 5) DMA - DMA, 6) FFF - CON or 7) FFF - FFF, followed by a standard layer diet through 18 weeks of age (WOA) to 42 WOA.3. Antibody titres against infectious bronchitis (IBV) and Newcastle disease (NDV) were measured at six days and six WOA, and plasma FA profile was measured at 18 and 42 WOA.4. Pullets from FFF-fed breeders had higher antibody titres against IBV and NDV than pullets fed DMA (P < 0.05). Feeding FFF to offspring increased plasma ∑n-3 FA at 18 and 42 WOA, whereas feeding DMA to offspring reduced ∑n-6 FA at 18 WOA.5. In conclusion, independent of breeder strain, alpha linoleic acid (ALA) and DHA sources showed varied responses. Feeding breeders FFF increased plasma concentration of antibody titres and n-3 FA whereas DMA reduced plasma concentration of ∑n-6 FA.

Profile of fatty acid lipid fractions of omega-3 fatty acid-enriched table eggs

The omega-3 fatty acid (FA) enrichment of yolk is a key means one of the main objectives to improve the nutraceutical properties of eggs. We evaluated the effect of the dietary inclusion of extruded linseed fed to laying hens on the fatty acid composition of the polar and non-polar lipid classes of the eggs. Two groups of 36 Lohmann White Leghorn layers (65 weeks old) were each fed one of two different diets for a period of 12 weeks. The two diets consisted of a conventional cereal-based diet concentrate (C) and a diet concentrate containing 5% linseed (L). The inclusion of linseed in the diet increased the content of α-linolenic (C18:3n-3), eicosapentaenoic (C20:5n-3) and docosahexaenoic (C22:6n-3) acids in neutral lipids, while a concomitant decrease in arachidonic acid (C20:4n-6) was observed. As regards the polar fraction, the fatty acid composition was slightly affected by the dietary treatments except for C18:0 (+1.14 fold), C18:2n-6 (+1.23 fold), C18:3n-3 (+2.8 fold) and C22:6n-3 (+1.41 fold). Principal component analysis demonstrated that very long-chain FAs were more representative of polar lipids, except for C20:5n-3, while neutral lipids were characterized by dietary n-3 FA (C18:3n-3).

Effects of feeding extruded flaxseed on layer performance, total tract nutrient digestibility, and fatty acid concentrations of egg yolk, plasma and liver

A study was conducted to determine the effects of graded levels of extruded flaxseed (EF) on laying hen performance, apparent total tract nutrient retention (ATTNR) and fatty acid concentrations of egg yolk, blood plasma and liver. Seventy-two White Leghorn layers (58 weeks old; three per cage) were randomly assigned to one of four dietary treatments: 0 (control), 3, 6 and 9% of EF-supplemented diets for 8 weeks. Results showed that feed intake, egg production, feed conversion ratio and egg weight were not affected by treatments. The ATTNR of dry matter (p = .001) and gross energy (p = .014) was lower for layers fed 9% EF than those fed the control diet, while ATTNR of organic matter (p = .001) and nitrogen-corrected apparent metabolizable energy (p = .003) were lower for birds fed 6% and 9% EF compared with those fed the control diet. Relative to the control diet, feeding EF increased (p < .001) egg yolk, plasma and liver n-3 polyunsaturated fatty acid (PUFA) concentrations. Birds fed 6% EF produced eggs > 300 mg of n-3 PUFA after two weeks of feeding, while the highest of n-3 PUFA concentrations were achieved for birds fed 9% EF. It was concluded that feeding EF up to 9% of the diet had no adverse effects on layer performance and increased n-3 PUFA concentrations in blood plasma, liver and egg yolk. However, moderate to high levels of EF (i.e., 6% and 9% of the diet) reduced nutrient ATTNR and nitrogen-corrected apparent metabolizable energy. Omega-3-enriched eggs can be achieved by feeding layers EF at 6% of the diet.

n-3 fatty acids fed to ISA brown and Shaver white breeders and their female progeny during rearing: Impact on egg production, eggshell, and select bone attributes from 18 to 42 weeks of age

The impact of feeding sources of n-3 fatty acids (FA) to ISA brown and Shaver white breeders and their female offspring during rearing on egg production, eggshell, tibia, and keel bone attributes was examined. Breeders were fed Control (CON) or CON + 1% dried microalgae (DMA: Aurantiochytrium limacinum) as the source of docosahexaenoic acid or CON + 2.6% of a coextruded mixture of full-fat flaxseed (FFF) and pulses as a source of α-linolenic acid. Day-old offspring were fed 1) breeder CON-pullet CON (CON-CON), 2) breeder CON-pullet DMA (CON-DMA), 3) breeder CON-pullet FFF (CON-FFF), 4) breeder DMA-pullet CON (DMA-CON), 5) breeder DMA-pullet DMA (DMA-DMA), 6) breeder FFF-pullet CON (FFF-CON), and 7) breeder FFF-pullet FFF (FFF-FFF). At 18 wk of age (WOA), pullets were fed a common layer diet to 42 WOA for egg production and bone quality assessments. There was no (P > 0.05) interaction between strains and diets and the main effect of diets on egg production, egg mass, and eggshell quality. There was an interaction (P = 0.008) between strain and diet on egg weight (EW); however, the strain effect on EW (P < 0.001) was such that ISA brown had heavier eggs than Shaver white. Shaver white had higher (P < 0.001) eggshell %, eggshell, and tibia breaking strength (BS), as well as tibia ash concentration compared with ISA brown hens. In contrast, ISA brown hens exhibited heavier (P < 0.05) tibia and keel bones. Feeding breeders DMA and pullets both sources of n-3 FA increased tibia medullary ash concentration compared with other diets (P < 0.001). Shaver white hens showed greater decline in tibia BS (83.7 vs. 96.3%) and ash content (84.1 vs. 94.3%) than ISA brown hens from 18 to 42 WOA (P < 0.05). Strain and diets exhibited independent effects on eggshell, tibia, and keel attributes. Provision of α-linolenic acid and docosahexaenoic acid to breeders and offspring improved tibia medullary ash concentration at 42 WOA.

Enriching ISA brown and Shaver white breeder diets with sources of n-3 polyunsaturated fatty acids increased embryonic utilization of docosahexaenoic acid

There is limited information on feeding egg-type chick breeders n-3 polyunsaturated fatty acids (PUFA) and its impact on hatching egg quality and embryonic fatty acid (FA) utilization. We investigated the effects of feeding brown and white egg-type chick breeders diets containing sources of n-3 PUFA on egg composition, apparent embryonic FA utilization, and intestinal FA transporter in hatchlings. Twenty-six-week-old ISA brown and Shaver white breeders were fed either 1) control (CON); 2) CON + 1% of microalgae (DMA, Aurantiochytrium limacinum) fermentation product, as a source of docosahexaenoic acid (DHA); or 3) CON + 2.60% of coextruded full-fat flaxseed and pulse mixture (FFF, 1:1 wt/wt) as a source of α-linolenic acid (ALA). Test diets had similar total n-3 and n-6:n-3 ratio. Eggs were hatched, and residual yolk (RY) samples taken for FA analyses. Apparent embryonic FA utilization was calculated by subtracting concentration of FA in RY from concentration of FA in yolk before incubation. There was an interaction between strains and diets (P < 0.05) on DHA in phospholipid and triglyceride fractions of yolk. Both n-3 PUFA sources increased DHA to a greater extent in Shaver white than in ISA brown. The interactive effect of strains and diets (P = 0.019) on embryonic utilization of ALA was such that DMA and FFF reduced ALA utilization, and this pattern was more prevalent in Shaver white birds than in ISA brown birds. There was no interaction between strains and diets on DHA utilization (P > 0.05). Embryos from hens fed n-3 PUFA sources used less total FA in phospholipid fraction (P < 0.001), and they preferentially used more DHA than CON embryos. Shaver white embryos used more (P < 0.05) ALA and DHA than ISA brown embryos. Although data suggested Shaver white had higher propensity of depositing DHA than ISA brown, irrespective of strain, feeding n-3 PUFA modified embryonic pattern of FA utilization toward utilization of DHA.

Feeding to Produce n-3 Fatty Acid-enriched Table Eggs

This study aimed to modify the feed mixtures of laying hens to enrich the consumer eggs with n-3 polyunsaturated fatty acids (PUFA): α-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). One hundred and twenty Tetra-SL laying hens used in the study were divided into three groups of 40 laying hens arranged in five repetitions: C, control with 5% soybean oil; E1, 0.5% fish oil + 0.5% microalgae Schizochytrium limacinum; and E2, 0.75% fish oil + 0.75% microalgae. The composition of the mixtures was balanced at the level of 17.5% raw protein and 11.81 MJ/kg metabolic energy (ME). Feed and water were provided ad libitum, and the experiment lasted for 21 days. In this study, the different physical and chemical properties of eggs, the fatty acid profile and lipid oxidation of fat in egg yolks were analyzed. The results of the study showed that the weight of the egg yolk and that of the shell depended on the feeding treatments (P=0.014 and P<0.001), and the weight of eggs and basic parts, as well as the thickness of the shell depended on the storage duration (P<0.001). The storage time affected the pH of egg yolks and albumen and the reduction in Haugh units and albumen height (P<0.001). Significant differences were observed in the content of ALA, DHA, ∑n-3 PUFA (mg/100 g) and the n-6/n-3 PUFA ratio between the C and E1/E2 egg groups (P<0.001). The results of the study indicate that it is sufficient to use a lower level of fish oil and the microalgae Schizochytrium limacinum in hens' feed to achieve a satisfactory increase in n-3 PUFA in eggs, while maintaining optimal values of egg quality and freshness indicators.

Long term effect of dietary lipid saturation on eggshell quality and bone characteristics of laying hens

This study investigated the long-term effect of dietary fatty acid saturation on eggshell quality and bone characteristics of laying hens at end of lay. Five isoenergetic (3,011.5 kcal AME/kg DM) and isonitrogenous (169 g CP/kg DM) diets were formulated using different lipid sources at a constant 30 g/kg inclusion level. The control, polyunsaturated omega-3 (PUFA n-3), polyunsaturated omega-6 (PUFA n-6), monounsaturated omega-9 (MUFA n-9), and saturated fatty acid (SFA) diets consisted of linseed- and fish oil (50:50 blend), fish oil, sunflower oil, high oleic acid sunflower oil, and tallow, respectively. A total of 200 individually caged Hy-Line Silver-Brown hens (20 wk of age) were randomly allocated to the 5 treatments (n = 40 replicates/treatment) and received the experimental diets for 54 wk. During weeks 58, 62, 66, 70, and 74 of age (end-of-lay period), 20 eggs/treatment per day (n = 140 eggs/treatment per week) were selected for determining eggshell quality traits. At 74 wk of age, 10 birds per treatment (n = 10 birds/treatment) were randomly selected for the determination of bone quality characteristics. Data were statistically analyzed (P < 0.05) using a fully randomized 1-way ANOVA. Dietary treatment had no effect (P > 0.05) on eggshell quality traits. The MUFA n-9 treatment with the highest unsaturated to SFA ratio (UFA: SFA) resulted in a higher (P < 0.05) femur weight (10.34 g) as well as femur- (52.99%) and tibia ash (51.07%) content than the SFA treatment. Also, the PUFA n-3 diet resulted in a higher (P < 0.05) femur weight (10.21 g), femur ash (51.82%), and percentage femur (0.57%) compared to the SFA diet. Results suggested that prolonged feeding of diets varying in FA profile had no negative effect on eggshell quality, whereas UFA: SFA and long-chain n-3 PUFA affected the bone quality (especially the femur) of hens at the end of lay.

Chemical-nutritional parameters and volatile profile of eggs and cakes made with eggs from ISA Warren laying hens fed with a dietary supplementation of extruded linseed

Objective

The aim of this study was to evaluate the chemical-nutritional parameters, oxidative stability and volatile profile of eggs and cakes made with eggs from laying hens fed with a dietary supplementation of extruded linseed.

Methods

Two thousand ISA Warren laying hens were randomly divided into two groups: a control group was fed with a standard diet while the experimental group received the same diet supplemented with 7% of extruded linseed. The trial lasted 84 days, in which three samplings of laid eggs were performed. Samples of eggs and food systems arising from eggs were then analyzed in order to obtain information about β-carotene and total flavonoid content, antioxidant activity, fatty acid profile, lipid oxidation, and volatile profile.

Results

Linseed induced the increase of α-linolenic acid with consequent reduction of the ω-6/ω-3 ratio (4.3:1 in egg yolk); in addition to this, was evidenced the cholesterol reduction and the significant increase in total flavonoids and β-carotene, although no variations were detected in antioxidant capacity. Even in cooked products there was not only a direct effect of linseed in increasing α-linolenic acid, but also in inducing the reduction of cholesterol and its major oxidation product, 7-ketocholesterol. The dietary linseed integration was also shown to affect the volatile profile of baked products.

Conclusion

Data confirmed that dietary supplementation with extruded linseed resulted in food products with interesting implications for human health. With regard to the volatile profile of baked products it would be necessary undertake further sensorial analysis in order to evaluate any variations on flavor and consumer acceptability.

Content of selected inorganic compounds in the eggs of hens kept in two different systems: organic and battery cage

Recent years have seen increased interest in the influence of bioactive dietary components on human genes and gene expression. A good source of many bioactive substances is the chicken egg. The egg is considered to be an excellent food provided by nature. It is a good source of nutrients such as vitamins A, B2, B6, B12, D, E and K, as well as elements including phosphorus, selenium, iron, zinc, magnesium and calcium. The research material use in this study consisted of eggs from hens kept in two different systems: organic and battery cages. The content of calcium (Ca), magnesium (Mg) and zinc (Zn) was determined in the egg contents - in the yolk and white respectively. The content of elements was determined by atomic absorption spectrometry (AAS) using an AA280 FS spectrometer with the automatic dilution of standards and samples. The eggs from the organically raised hens had a higher calcium, magnesium and zinc content. The greater variation in the Ca, Mg and Zn content in the organic eggs is due to the more individualized feeding system. The rearing system of the hens significantly affects the concentration of elements in the egg. The results of this research indicate that eggs from organic farming systems have a richer chemical composition in terms of the content of nutrients such as calcium, magnesium and zinc compared with eggs obtained from caged hens. Therefore, consumers purchasing eggs should consider the system in which the hens were reared, as eggs can be a valuable source of these elements in the diet.

Dynamics of thymol dietary supplementation in quail (Coturnix japonica): Linking bioavailability, effects on egg yolk total fatty acids and performance traits

Phytogenic additives such as thymol are encountering growing interest in the poultry industry. However, there are still questions concerning dynamics of their bioavailability, biological action, optimal dosage and duration of supplementation needed to achieve meaningful effects, as well as persistence of induced changes after supplement withdrawal. We studied the link between the dynamics of free thymol concentration and the changes in fatty acids composition in quail egg yolk, both during a month-long chronic dietary supplementation and after 3 weeks of supplement withdrawal (post-supplementation). Fifty, 85 days-old, female quail of homogeneous body weights (251±1g) in egg-laying peak were used. To evaluate potential dose-dependent effects, three increasing doses 2, 4, and 6.25 g of thymol/kg of feed (THY2, THY4 and THY6, respectively) and two controls were evaluated (n = 10). In parallel, we assessed the concomitant changes in free thymol excretion, potential liver histopathological changes, and birds´ performance traits. Egg yolk and droppings show a dose-dependent increase in THY concentration after 9 days of supplementation and a decrease after post-supplementation. In egg yolk, these changes were accompanied by reduced saturated fatty acid concentrations achieved by 28 days of supplementation in THY2 and 14 days of supplementation in THY4 and THY6. However, after post-supplementation the aforementioned effect disappeared in THY2 but not in THY4 and THY6. While THY2 failed to increase polyunsaturated fatty acids, THY4 and THY6 increased polyunsaturated fatty acids by day 14 of supplementation and remained increased after post-supplementation. Fatty acids changes induced by thymol are consistent with improved nutritional quality of eggs. No treatment effects were observed in liver histopathology and female performance. Findings suggest that both dose of thymol and duration of supplementation modulate thymol and fatty acids concentrations in egg yolk and thymol concentration in droppings. Furthermore, the persistence of those effects after post-supplementation period is also a dose-dependent phenomenon.

Inclusion of pyridoxine to flaxseed cake in poultry feed improves productivity of omega-3 enriched eggs

Flaxseed cake produced during flax oil production is rich in protein, and could be utilized in the production of omega-3 enriched eggs or value added eggs. But the presence of anti-nutrients in flaxseed cake adversely affects the bird and egg characteristics. Supplementation of pyridoxine may prove beneficial as noted by earlier research. In our study, we divided 30 layer birds into three groups and supplemented them with different combination feeds containing: (A) control ration, (B) fresh flax seed cake with pyridoxine and (C) fresh flax seed cake without pyridoxine. Crushed 2% flaxseed was also added to the flaxseed cake groups for deposition of sufficient omega-3 fatty acids into the eggs. Supplementation was given for a period of 4 weeks and egg as well as bird characteristics observed. Birds fed pyridoxine showed better incorporation of omega-3 fatty acids into the egg yolk. Supplementation of flaxseed cake with pyridoxine resulted in better yields of omega-3 eggs as well as improved health of layer birds.

The Golden Egg: Nutritional Value, Bioactivities, and Emerging Benefits for Human Health

Egg is an encapsulated source of macro and micronutrients that meet all requirements to support embryonic development until hatching. The perfect balance and diversity in its nutrients along with its high digestibility and its affordable price has put the egg in the spotlight as a basic food for humans. However, egg still has to face many years of nutritionist recommendations aiming at restricting egg consumption to limit cardiovascular diseases incidence. Most experimental, clinical, and epidemiologic studies concluded that there was no evidence of a correlation between dietary cholesterol brought by eggs and an increase in plasma total-cholesterol. Egg remains a food product of high nutritional quality for adults including elderly people and children and is extensively consumed worldwide. In parallel, there is compelling evidence that egg also contains many and still-unexplored bioactive compounds, which may be of high interest in preventing/curing diseases. This review will give an overview of (1) the main nutritional characteristics of chicken egg, (2) emerging data related to egg bioactive compounds, and (3) some factors affecting egg composition including a comparison of nutritional value between eggs from various domestic species.

Effect of omega-3 and omega-6 fatty acid inclusion in broiler breeder's diet on laying performance, egg quality, and yolk fatty acids composition

The present study was conducted to evaluate the effect of different dietary oil sources (omega-3 and omega-6 fatty acid) in female broiler breeders’ diets on laying performance, egg quality and yolk fatty acids composition. Ross-308 breeders (220; 25 weeks old) were used in this experiment for 6 weeks. Birds were placed in a complete randomized design with 4 dietary treatments (containing 2% soybean oil, 2% sunflower oil, 2% flaxseed oil, and 2% fish oil) and 5 replications containing 1 male + 10 females in each pen having a similar body weight (3,424 g) and egg production (86%). Results indicated that different sources of dietary oil had no significant effect on body weight gain, feed conversion ratio, and egg production but had a significant effect on egg weight. Also feeding the diets containing 2% of different fatty acids had a significant effect on some egg quality parameters and egg yolk fatty acids composition. It was concluded that inclusion of 2% flaxseed oil can improve laying performance, egg quality, and egg yolk fatty acids composition parameters in broiler breeders.

Comparative omega-3 fatty acid enrichment of egg yolks from first-cycle laying hens fed flaxseed oil or ground flaxseed

When laying hen diets are enriched with omega-3 polyunsaturated fatty acids to generate value-added eggs for human consumption markets, concentrations of alpha-linolenic (ALA), eicosapentaenoic (EPA), and docosahexaenoic acids (DHA) in the yolk can reach 250 mg/50 g whole egg. Flaxseed, a rich source of ALA, is commonly used for omega-3 enrichment; however, the impact of dietary flaxseed source (extracted oil vs. milled seed) on fatty acid transfer to egg yolk in laying hens is unknown. Therefore, transfer of ALA, EPA, and DHA into egg yolk from extracted flaxseed oil or milled flaxseed was evaluated in Hy-Line W-36 laying hens over an 8-week feeding period (25 to 33 wk old). Hens (n = 132) were randomly housed with 3 birds/cage (4 replicates/treatment) for each of the 11 treatment groups. Diets were isocaloric and consisted of a control diet, 5 flaxseed oil diets (0.5, 1.0, 2.0, 3.0, or 5.0% flaxseed oil), and 5 milled flaxseed diets (calculated flaxseed oil concentration from milled flaxseed 0.5, 1.0, 2.0, 3.0, 5.0%). Increasing dietary concentrations of flaxseed oil and milled flaxseed resulted in increased ALA, EPA, and DHA concentration in egg yolk, and fatty acid deposition from flaxseed oil was 2 times greater compared to milled flaxseed when fed at the same dietary inclusions (P < 0.01). Egg yolk EPA and DHA concentrations were not different due to oil or milled source (P = 0.21); however, increasing dietary inclusion rates of flaxseed oil from either source increased yolk EPA and DHA (P < 0.01). Hens fed either flaxseed oil or milled flaxseed resulted in reduced BW change as dietary concentrations increased (P = 0.02). Feed efficiency increased as flaxseed oil increased in concentration, while feeding milled flaxseed decreased feed efficiency (P = 0.01). Analysis of the nitrogen corrected apparent metabolizable energy of flaxseed oil resulted in 7,488 kcal/kg on an as-fed basis. Dietary flaxseed oil improved feed efficiency and increased ALA deposition into yolk compared to a milled source, demonstrating flaxseed oil to be a viable alternative for ALA egg enrichment.

Effects of extruded flaxseed on layer performance, nutrient retention and yolk fatty acid composition

1. This study was conducted to determine the effects of feeding an extruded flaxseed (EF) on layer performance, apparent total tract nutrient retention (ATTR) and egg yolk fatty acid concentrations. 2. Seventy-two White Leghorn laying hens (58-week-old; three per cage) were randomly allotted to one of four dietary treatments: 0%, 7.5%, 15.0% and 22.5% of EF-supplemented diets for 8 weeks. 3. Supplementation with EF had no effect on feed intake, egg production, feed conversion ratio and egg weight. Egg components (yolk, albumen and shell percentages) were similar among treatments, except that shell percentage was greater for layers fed 22.5% EF than those fed 7.5% and 15% EF. The ATTR of dry matter and organic matter were highest for 0% and 7.5% EF, intermediate for 15% EF and lowest for 22.5% EF. Similar reductions on ATTR of crude protein and nitrogen-corrected apparent metabolisable energy were observed for layers fed 22.5% EF relative to those fed 0% or 7.5% EF. 4. Feeding EF at 7.5%, 15.0% and 22.5% of the diet markedly increased (by 92%, 198% and 271%, respectively) egg yolk concentrations of n-3 polyunsaturated fatty acid (PUFA) and reduced saturated fatty acid and n-6 PUFA concentrations. 5. It was concluded that omega-3 labelled eggs (300 mg/60 g of egg) may be produced with low (7.5% of diet) levels of dietary EF without compromising egg production parameters. However, feeding moderate to high levels of EF (i.e. 15% and 22.5% EF) may reduce total tract nutrient and energy utilisation.

Dietary choline and phospholipid supplementation enhanced docosahexaenoic acid enrichment in egg yolk of laying hens fed a 2% Schizochytrium powder-added diet

The aim of this study was to evaluate the effect of dietary phospholipid supplementation on laying hen performance, egg quality, and the fatty acid profile of egg yolks from hens fed a 2% Schizochytrium powder diet. Three-hundred-sixty 28-wk-old Hy-line W-36 laying hens were randomly allocated to one of the 5 dietary treatments, each treatment with 6 replicates of 12 birds each. All diets included 2% Schizochytrium powder (docosahexaenoic acid [DHA], 137.09 mg/g). The control group was not supplemented with any additional phospholipids, whereas the other 4 experimental diets were supplemented with 1,000 mg/kg choline (CHO), 1,000 mg/kg monoethanolamine (MEA), 1,000 mg/kg lysophosphatidylcholine (LPC), or 500 mg/kg LPC + 500 mg/kg MEA (LPC + MEA). The experimental diets were isocaloric (metabolizable energy, 11.15 MJ/kg) and isonitrogenous (crude protein, 16.60%). The feeding trial lasted 28 days. Laying hen performance and egg quality were not affected (P > 0.05) by the diets used. The monounsaturated fatty acid (MUFA) level was reduced in the LPC group at d 28 (P < 0.01), whereas the polyunsaturated fatty acid (PUFA) level was increased (P < 0.05). The omega-6 (n-6) PUFA level of the egg yolks in the LPC group had a trend to increase in comparison to the control (P = 0.07). The CHO and LPC groups had higher omega-3 (n-3) PUFA and DHA levels and lower n-6/n-3 ratios than the other groups at d 28 (P < 0.01). The DHA content in egg yolk reached a plateau after the laying hens consumed the experimental diets for 14 days, and higher yolk DHA contents were observed in the CHO and LPC groups as compared with the other groups at d 14. It was concluded that dietary choline supplementation for more than 14 d enhanced egg yolk enrichment with n-3 PUFA and DHA when laying hen diets were supplemented with 2% Schizochytrium powder. All the diets had no adverse effect on hen performance, egg quality, or egg components under the experimental condition.

Dietary High-Oleic Acid Soybean Oil Dose Dependently Attenuates Egg Yolk Content of n-3 Polyunsaturated Fatty Acids in Laying Hens Fed Supplemental Flaxseed Oil

Chickens can hepatically synthesize eicosapentaenoic acid (20:5 n-3) and docosahexaenoic acid (22:6 n-3) from α-linolenic acid (ALA; 18:3 n-3); however, the process is inefficient and competitively inhibited by dietary linoleic acid (LNA; 18:2 n-6). In the present study, the influence of dietary high-oleic acid (OLA; 18:1 n-9) soybean oil (HOSO) on egg and tissue deposition of ALA and n-3 polyunsaturated fatty acids (PUFA) synthesized from dietary ALA was investigated in laying hens fed a reduced-LNA base diet supplemented with high-ALA flaxseed oil (FLAX). We hypothesized that reducing the dietary level of LNA would promote greater hepatic conversion of ALA to very long-chain (VLC; >20C) n-3 PUFA, while supplemental dietary HOSO would simultaneously further enrich eggs with OLA without influencing egg n-3 PUFA contents. Nine 51-week-old hens each were fed 0, 10, 20, or 40 g HOSO/kg diet for 12 weeks. Within each group, supplemental dietary FLAX was increased every 3 weeks from 0 to 10 to 20 to 40 g/kg diet. Compared to controls, dietary FLAX maximally enriched the total n-3 and VLC n-3 PUFA contents in egg yolk by 9.4-fold and 2.2-fold, respectively, while feeding hens 40 g HOSO/kg diet maximally attenuated the yolk deposition of ALA, VLC n-3 PUFA, and total n-3 PUFA by 37, 15, and 32%, respectively. These results suggest that dietary OLA is not neutral with regard to the overall process by which dietary ALA is absorbed, metabolized, and deposited into egg yolk, either intact or in the form of longer-chain/more unsaturated n-3 PUFA derivatives.

Thymol feed supplementation in quail alters the percentages of nutritionally relevant egg yolk fatty acids: effects throughout incubation

BACKGROUND

Polyunsaturated fatty acids (PUFA) are crucial components of egg yolk and particularly prone to oxidative damage, generating losses of nutrients for embryonic development and influencing the quality of eggs for human consumption. The aim of this study was to evaluate whether dietary thymol (a natural antioxidant) is related to changes in quail egg yolk total (T), triglyceride (TG) and phospholipid (PL) fatty acid composition at different stages of embryo development. Thus female Japanese quail (100 days of age) were assigned to one of two dietary treatments (12 individuals each): CON (basal diet) or THY (0.0016 mol thymol day^-1 per bird). After 2 weeks of supplementation, eggs were incubated and samples were obtained at 0, 4 and 16 days of embryonic development.

RESULTS

In 0 day THY eggs, α-linolenic acid and n-3 PUFA in T and TG, docosahexaenoic acid and PUFA in T and arachidonic acid in TG were increased, while saturated fatty acids (SFA) in T were reduced. From 4 days on, PUFA, n-3 PUFA and SFA from T and TG in THY eggs were found to be similar to those of CON eggs. The changes in PL throughout incubation were similar in both dietary treatments.

CONCLUSION

Thymol would provide the embryo with PUFA for synthesis/deposition in membranes and/or assign to supply energy. Additionally, thymol supplementation would be advisable for the production of healthier table eggs. © 2017 Society of Chemical Industry.

Nutritional modulation of health, egg quality and environmental pollution of the layers

World egg production and consumption have been increasing for the past decades. Traditional strategies in poultry nutrition have made vital contributions to this great growth in quantity. However, current global issues should be considered in modern egg production such as growing populations and food security, food safety and quality, limited resources and environmental problems. The development of knowledge of poultry nutrition and modern biotechnology provides novel nutritional approaches to closely fit the requirement of pullets and laying hens, which will consequently decrease the nutrition excretion and maintain the lower cost of feed. Nutrition has also been widely accepted as a strategy to influence health and diseases of laying hens. The maintenance of good health is an important prerequisite for improving productivity and egg quality. In addition, there are many measures and strategies for minimizing the incidence of egg defects and providing a choice of lifestyle to enhance human health. This paper reviews current research progress on developing innovative technologies and strategies to maximize animal health and performance, improve the quality of egg products and minimize pollution caused by poultry production.

Hyphenated Analytical Methods in Determination of Biologically Active Compounds in Hen's Eggs

Hen's egg is a complete material needed for the development of the embryo; it is an important source of nutraceutical compounds, such as protein, fats, vitamins, trace metals, and minerals. Moreover, avian egg contains biologically active compounds that exhibit antibacterial and antimicrobial activities as well as antitumor, antiviral, antioxidant, immunomodulating, and therapeutic properties. Eggs are mostly very good sources of valuable, easily digestible proteins. This review focuses on the biologically active compounds from hen's egg and applications of these compounds in medicine and the pharmaceutical industry. Additionally, it gives an overview of the hyphenated separation techniques, including sample preparation, analysis, and identification, used in the proteomics and lipidomics analysis.

Camelina sativa cake for broilers: Effects of increasing dietary inclusion from 0 to 24% on tissue fatty acid proportions at 14, 28, and 42 d of age

The benefits to human from the consumption of omega-3 polyunsaturated fatty acids (N-3 PUFAS) have been recognized. Camelina sativa is an oilseed crop grown for biofuel production. Feeding its cake with 10 to 20% remaining oil (28 to 30% α-linolenic acid [ALA]) has the potential to enrich poultry products with n-3 PUFA. An experiment was conducted to assess lipid deposition in brain, liver, breast, and thigh tissue by increasing inclusions of camelina cake (CC) fed to broiler chickens. Male chicks (744, Ross 308) housed in 24 cages were fed 0, 8, 16, or 24% CC for 42 d, 6 replicates per CC level. At the end of the starter (14 d), grower (28 d), and finisher (42 d) phase, brain, liver, breast, and thigh samples were collected from 3 birds/cage and diets were analyzed for fatty acid content. Feeding increasing CC inclusions from 0 to 8, 16, and 24% increased dietary ALA (5.3, 11.1, 15.2, 17.8, respectively) as a proportion of the total fatty acid content. All diets provided a similar level of long-chain n-3 PUFA (about 0.9%). Irrespective of growth phase, increases in dietary CC inclusion led to a linear increase (P<0.001) in the proportion of ALA in breast, thigh, and liver (76, 128, 288%, respectively), but not in brain tissue. An increase in dietary CC inclusion led to a linear increase (P<0.001) in the proportion of long-chain n-3 PUFAs, including docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) in liver (109 and 80%, respectively) and brain (24 and 6%, respectively) tissue. However, in breast and thigh tissue, increases in dietary CC inclusion led to an increase in only (P<0.005) DPA (24 and 27%, respectively). The predominant n-3 PUFA in liver and brain tissue feeding 24% CC was DHA (48% and 88%, respectively), unlike in breast and thigh meat, where ALA increased (65 and 86%, respectively). The labeling claim requirement for n-3 PUFA enrichment (300 mg/100 g meat) was exceeded in breast and thigh by feeding a 24% CC diet for 28 d or 16% CC diet for 42 d, respectively.