Yolk Cholesterol Content Research Articles

Effects of corn dried distillers’ grains with solubles on performance, egg quality, yolk fatty acid composition and oxidative status in laying ducks

The study investigated the effects of increasing content of corn distillers’ dried grains with solubles (DDGS) in the diets of laying ducks on oxidative status, laying performance, egg quality, and egg yolk fatty acid composition. Longyan females (1080) with similar BW at 17 wk of age were randomly assigned to 6 treatment groups, each consisting of 6 replicates of 30 birds. The basal diet (I) was a typical corn-soybean ration while the experimental diets (II to VI) substituted corn DDGS for soybean meal and wheat bran and a small reduction of corn. The level of substitution in diets (II to VI) was 6%, 12%, 18%, 24% and 30%. The experiment lasted for 18 wk. Average egg weight decreased linearly as the level of corn DDGS inclusion increased (P < 0.001). Haugh unit, albumen weight, and proportion declined as linear responses to corn DDGS substitution (P < 0.05), but yolk color linearly increased (P < 0.001); the proportions of oleic (C18:1) and total monounsaturated fatty acids in egg yolk linearly decreased with increasing corn DDGS and many of the key polyunsaturated fatty acids (PUFAs) like linoleic (C18:2n-6), arachidonic (C20:4n-6) and α-linolenic (C18:3n-3) acids linearly increased (P < 0.001), but not those of eicosapentaenoic (C20:5n-3) and docoshexaenoic (C22:6n-3) acids. The PUFAs n-6/n-3 ratio linearly increased with increasing corn DDGS level (P < 0.001). Increasing corn DDGS linearly increased hepatic expression of GPX1, HO-1, and Nrf2 and hepatic activity of GSH-Px and the liver content of MDA (P < 0.001). There were no treatment effects on egg production, egg mass, feed conversion ratio, eggshell thickness, strength, and yolk cholesterol content (P > 0.05). In conclusion, the current study indicates that the use of corn DDGS is possible as a replacement, primarily for soybean meal at levels up to 18% in the diets of laying ducks without affecting laying performance, egg quality, and antioxidant status. Increasing amounts of corn DDGS linearly increased egg yolk concentrations of key fatty acids like like C18:2n-6 and C18:3n-3 and the antioxidant enzyme activity of GSH-Px through the Nrf2 pathway to avoid oxidative stress.

Assessment of Effects of Prebiotics Supplementation on Feed Intake, Egg and Serum Cholesterol Levels in White Leghorn Layers

The present study was undertaken to evaluate the effect of supplementation of graded levels of prebiotics on feed intake, egg yolk cholesterol, serum cholesterol levels and internal egg quality parameters in White Leghorn layers. An experiment trial was run for a period of 16 weeks with eighty White Leghorn layers in the age group of 22–23 weeks of age were allotted randomly to four dietary treatments having 4 replications with 5 birds each. The control diet (T1) was formulated as per the BIS (2007) meeting the requirements for laying phase of the hens in the age group of 22–38 weeks. In addition, the birds in treatments T2, T3 and T4 were supplemented with prebiotics (containing mannonoligosacchrides of the Saccharomyces cell wall-47 g, formic acid (85%)-32 g, HSCAS upto 1 kg) @ 0.5, 1.0 and 2.0 g/kg of feed, respectively. Laying hens receiving prebiotics exhibited improvement in feed conversion ratio of 3.83 and 7.34% in treatment groups T3 and T4, respectively compared to control. The prebiotics supplementation showed positive effect on internal egg quality parameters viz. albumen index, yolk index and Haugh unit in layers supplemented with graded levels of the prebiotics as compared to the control group. Maximum increase of 1.92% in albumen index and 2.06% in Haugh unit was observed in treatment T4 as compared to T1. However, no significant effect was observed for yolk index. Also, a significant (P<0.05) reduction was observed in the serum as well as egg yolk cholesterol and low density lipoproteins (LDL) concentrations while egg yolk high density lipoproteins (HDL) concentrations were not affected. Thus, the present study showed that administration of prebiotics had positive effect on serum and egg cholesterol levels without any changes in HDL levels.

Synergetic effects of essential oils mixture improved egg quality traits, oxidative stability and liver health indices in laying hens fed fish oil

Omega-3 fatty acids are necessary for human health, although products containing higher proportions of these fatty acids make them more susceptible to lipid peroxidation. The current study was conducted to evaluate the synergetic effects of dietary supplementation of herbal essential oils mixture (Thymus vulgaris, Mentha piperita, Rosmarinus officinalis and Anethum graveolens) and dietary fat sources on egg quality traits, oxidative stability and liver health indices of laying hens. A total of 150 laying hens were randomly distributed among 6 experimental treatments with five replicates of five birds each. Dietary treatment consisted of three levels of herbal essential oils mixture (0, 100 and 200mg/kg) and two sources of fat (fish oil and soybean oil containing different ratios of n-6 to n-3 fatty acids) that fed during an 80 d feeding trial. The results showed that administrating fish oil, containing low ratio of n-6 to n-3 fatty acids, enhanced liver (P<0.05) malondialdehyde concentration, egg yolk color (P<0.05), and led to the reductions in liver relative weight, hepatic lipid percentage (P<0.05), serum alkaline phosphatase activity (P<0.01), as well as serum and egg yolk cholesterol contents (P<0.05). Moreover, herbal essential oils mixture resulted in the declines in blood cholesterol and triglyceride concentrations (P<0.01), enzymes activity of alanine aminotransferase and aspartate aminotransferase (P<0.01), as well as hepatic and serum malondialdehyde concentrations (P<0.05). Also, it caused the improvements in eggshell hardness and thickness (P<0.05). In general, the findings indicated that although dietary administration of fish oil increased the susceptibility of serum and liver to lipid peroxidation, feeding 200mg/kg essential oils mixture resulted in the best systemic and hepatic antioxidant responses, the modulated serum lipid profiles, and also the improved eggshell quality.

Comparison of the effects of dietary supplementation of flavonoids on laying hen performance, egg quality and egg nutrient profile

ABSTRACT1. The aim of this experiment was to compare the effects of dietary supplementation of hesperidin, naringin and quercetin on laying hen performance, egg quality and egg yolk lipid and protein profiles.2. A total of 96 Lohmann White laying hens weighing an average of 1500 g at 28 weeks of age were randomly assigned to a basal diet and the basal diet supplemented (0.5 g/kg) with either hesperidin, naringin or quercetin. Each treatment was replicated in 6 cages in an 8-week experimental period. Data were analysed using one-way analysis of variance.3. None of the dietary flavonoids affected laying performance and eggshell quality. Hesperidin and quercetin supplementations decreased albumen and yolk indexes.4. As compared to the control group, egg yolk cholesterol content decreased and egg yolk protein content increased in response to dietary hesperidin and quercetin supplementation. The mean egg yolk cholesterol (mg/g) and protein (g/100 g) contents were 10.08/14.28, 16.12/14.08, 14.75/15.04 and 15.15/14.85 for the control group and groups supplemented with naringin, hesperidin and quercetin, respectively.5. Egg yolk lipid and protein profiles were variable.6. In conclusion, dietary supplementation of hesperidin or quercetin could be used in the diets during the early laying period to reduce egg yolk cholesterol and increase egg yolk protein, which may be attractive to consumers.

The effect of essential oils on quality and mineral composition of eggshell

The effect of essential oils on quality and mineral composition of eggshell

Effect of Water Extract of Two Leaves (Allium sativum and Sauropus androgynus) on Egg Production and Yolk Cholesterol Levels in Egg Laying Hens

ABSTRACT: Objective: The present study was conducted to determine the effects of sweet leaf (Sauropus androgynus) and Garlic (Allium sativum) leaves water extract on the egg production and yolk cholesterol level of 30 weeks aged of egg laying hens. Material and Methods: Ninety, 30-wk-old hens were colony caged in an environmentally controlled house to evaluate the effect of garlic and sweet leaf (Katuk, Indonesian) leaves water extract administration on hens. Sweet leaf and garlic extract was prepared by maceration sweet leaf and garlic leaves in distilled water (1:1, w/w). Hens were randomly divided into three equal groups; one served as a control, which administered with drinking water only, and the other two groups were administered with 5% water extract of sweet leaf or garlic leaves, resvectively. Results: Garlic and sweet leaf water extract increased (p 0,05). Garlic or sweet leaf water extract administration results in lower (p<0.05) serum and yolk cholesterol contents Conclusion: Garlic or sweet leaf water extract increased egg production, but decrease both serum and yolk cholesterol contents of egg laying hens. Ker words: Garlic, sweet leaf (katuk), cholesterol, egg laying hens

Evidence on the stability of histone H1.a polymorphic variants during selection in quail

Abstract. The goal of this work was to check whether selection for quantitative traits may cause a change in the histone H1 allelic complement and whether it can therefore be considered a modulator of histone H1-dependent chromatin functioning. For this purpose, a fluctuation of histone H1.a polymorphic variants was analyzed among a non-selected (control) quail line and the line selected for a high cholesterol content in the egg yolk. The histone H1.a was found to be polymorphic due to its differential migration rate in the AU-PAGE (acetic acid–urea polyacrylamide gel electrophoresis). Based on this, two H1.a isoforms (H1.a1 and H1.a2) that form three phenotypes (a1, a2 and a1a2) were distinguished in the quail lines tested. A comparably expressed (p &gt; 0. 05) and low relative variable (coefficient of variation, CV &lt; 0. 25) histone H1.a phenotypes were in agreement with Hardy–Weinberg equilibrium (HWE) in both the non-selected (χ2 = 1. 29, p = 0. 25) and selected (χ2 = 1. 9, p = 0. 16) quail line. The similarity among quail lines was assessed based on the equal distribution of histone H1.a phenotypes (χ2 = 1. 63, p = 0. 44) and alleles (χ2 = 0. 018, p = 0. 89) frequency in both quail lines tested. This indicates that selection does not affect the histone H1.a polymorphic variants. The stability of histone H1.a during selection might suggest that likely chromatin processes coupled to the selected trait are not linked to the activity of histone H1.a.

Polyphenols in Eucalyptus leaves improved the egg and meat qualities and protected against ethanol-induced oxidative damage in laying hens.

Polyphenols in Eucalyptus leaves (PE) were value resources due to various pharmacological activities, but data on the effect on laying hens are very scare. This study was conducted to determine the effect of PE on the laying performance, egg traits, meat quality, antioxidant status and liver tissues of laying hens. One hundred and twenty 256-day-old Yueqinhuang laying hens were randomly assigned to four treatment groups (different levels of PE at 0, 0.5, 0.8 and 1.2g/kg diet) for 63days with 15 replicates per group. Addition of 0.8g/kg PE not only improved the egg trait by increasing the eggshell thickness and decreasing MDA production and cholesterol content in the egg yolk, but also significantly enhanced meat quality of hens, as suggested by the increase pH45min (p<.01) and a* value, and decrease drip loss rate (p<.01). Meanwhile, under acute ethanol-induced oxidative damage condition, supplementation of 0.8g/kg PE enhanced the serum antioxidant status by increasing enzymatic activities (GSH-PX, T-SOD, T-AOC), inhibited oxidative damage and provided protective effect to liver tissue. In conclusion, addition of 0.8g/kg PE not only improved the egg traits and meat quality without obvious adverse effects, but also increased the serum antioxidant status of the hens and protected their liver tissue from ethanol-induced oxidative damage. This study indicated that PE could be utilized as an effective feed additive for laying hens to improve health performance and egg traits.

Effect of feeding different levels of dietary copper on production performance, egg quality traits, serum and egg yolk cholesterol content in laying quails

An experiment was conducted with CARI Uttam laying quails (n=120) during 11 to 24 weeks of age to evaluate optimum dietary copper (Cu) level for egg production, egg quality traits, serum and egg yolk cholesterol content. A basal diet having 20% protein and 2700 kcal ME/kg and 5mg Cu/kg was prepared. Five other experimental diets were formulated by addition of Cu sulphate to achieve 10, 15, 100, 150 and 200 mg Cu/kg diet. Each of such diet was offered as mash ad-libitum to laying quails randomly divided into six treatment groups with 10 replicates of two birds each reared in quail laying cages. Significantly (P<0.05) lower egg production was observed at 200mg Cu/kg diet than those fed other diets. The body weight change, feed conversion ratio, egg weight and egg quality traits did not differ significantly due to different dietary treatments. The cholesterol content in egg yolk was significantly(P<0.05) lower in groups fed diets containing 100, 150 and 200 mg Cu/kg diets than other dietary groups at both 45 and 90 days of feeding period. The serum total cholesterol content was also significantly (P<0.05) lower in 100, 150 and 200 mg Cu/kg dietary groups. Based on the results, it was concluded that for optimum production performance and egg quality traits laying quails required 5 mg Cu/kg diet, but feeding copper at 100 mg/kg diet, decreased the egg yolk and serum cholesterol content by 19% and 27%, respectively without affecting the production performance.

Performance and egg quality of laying hens fed flaxseed: highlights on n-3 fatty acids, cholesterol, lignans and isoflavones

Flaxseed is a rich source of α-linolenic acid and phytoestrogens, mainly lignans, whose metabolites (enterodiol and enterolactone) can affect estrogen functions. The present study evaluated the influence of dietary flaxseed supplementation on reproductive performance and egg characteristics (fatty acids, cholesterol, lignans and isoflavones) of 40 Hy-Line hens (20/group) fed for 23 weeks a control diet or the same diet supplemented with 10% of extruded flaxseed. The flaxseed diet had approximately three times the content of lignans (2608.54 ng/g) as the control diet, mainly secoisolariciresinol diglucoside (1534.24 v. 494.72 ng/g). When compared with the control group, hens fed flaxseed showed a similar deposition rate (72.0% v. 73.9%) and egg yield. Furthermore, there was no effect of flaxseed on the main chemical composition of the egg and on its cholesterol content. Estradiol was higher in the plasma of the control group (1419.00 v. 1077.01 pg/ml) probably due to the effect of flaxseed on phytoestrogen metabolites. The plasma lignans were higher in hens fed flaxseed, whereas isoflavones were lower, mainly due to the lower equol value (50.52 v. 71.01 ng/ml). A similar trend was shown in eggs: the flaxseed group had higher level of enterodiol and enterolactone, whereas the equol was lower (198.31 v. 142.02 ng/g yolk). Secoisolariciresinol was the main lignan in eggs of the flaxseed group and its concentration was three times higher then control eggs. Flaxseed also improved the n-3 long-chain polyunsaturated fatty acids of eggs (3.25 v. 0.92 mg/g egg), mainly DHA, however, its oxidative status (thiobarbituric reactive substances) was negatively affected. In conclusion, 10% dietary flaxseed did not affect the productive performance of hens or the yolk cholesterol concentration, whereas the lignans and n-3 polyunsaturated fatty acid content of eggs improved. Further details on the competition between the different dietary phytoestrogens and their metabolites (estrogen, equol, enterodiol and enterolactone) should be investigated.

Effect of flaxseed oil and microalgae DHA on the production performance, fatty acids and total lipids of egg yolk and plasma in laying hens

The incorporation of omega-3 polyunsaturated fatty acids (PUFA) in the egg is dependent on both the transfer efficiency of preformed dietary omega-3 fatty acids to the eggs as well as endogenous PUFA metabolism and deposition. Employing an experimental design consisting of 70 Lohmann LSL-Classic hens (n=10/treatment) in a 6-week feeding trial, we examined the impact of graded levels of either flaxseed oil (alpha-linolenic acid, ALA) or algal DHA (preformed docosahexaenoic acid, DHA), each supplying 0.20%, 0.40% and 0.60% total omega-3s. The control diet was practically low in omega-3s. Study parameters included monitoring the changes of fatty acid contents in yolk, measures of hen performance, eggshell quality, total lipids and fatty acid contents of plasma. Data were analysed as a complete randomized design using Proc Mixed procedure of SAS. No significant differences were observed between treatments with respect to hen performance, eggshell quality and cholesterol content in plasma and egg yolk. Individual and total omega-3 PUFA in the yolk and plasma increased (P<0.0001) linearly as a function of total omega-3 PUFA intake. At the highest inclusion levels, DHA-fed hens incorporated 3-fold more DHA in eggs compared with ALA-fed hens (179±5.55 vs. 66.7±2.25mg/yolk, respectively). In both treatment groups, maximal enrichment of total n−3 PUFA was observed by week-2, declined by week-4 and leveled thereafter. In addition, accumulation of DHA in egg yolk showed linear (P<0.0001) and quadratic (P<0.05) effects for flaxseed oil (R2=0.89) and algal DHA (R2=0.95). The current data, based on defined level of total omega-3s in the background diet, provides evidence to suggest that exogenous as well as endogenous synthesis of DHA may be subject to a similar basis of regulation, and serve to highlight potential regulatory aspects explaining the limitations in the deposition of endogenously produced omega-3 LCPUFA.

Effects of Curcuma longa rhizome powder on egg quality, performance and some physiological indices of laying hens fed different levels of metabolizable energy.

High-energy diets of laying hens may improve roductive performance, although some negative effects may also appear with respect to egg quality and physiological parameters. Curcuma longa rhizome powder (CRP) has beneficial effects on health indices of the birds through antioxidant and antimicrobial properties, especially when the birds experience nutritional stress. Increasing dietary CRP enhanced egg quality by improving eggshell thickness and hardness but decreasing yolk cholesterol content (P < 0.05). The best feed conversion ratio was obtained in birds fed high-apparent metabolizable energy (AME) diets supplemented with 2.0 g kg-1 CRP (P < 0.05). Although increasing dietary AME elevated the serum concentration of triglycerides (P < 0.05) and enzymatic activities of alanine aminotransferase and aspartate aminotransferase (P < 0.05), dietary inclusion of CRP alleviates the blood levels of these enzymes (P < 0.01). Low level of dietary CRP boosted the immune responses to Newcastle virus (P < 0.01) and sheep red blood cells (P < 0.05) antigens but decreased the heterophil to lymphocyte ratio (P < 0.05). Inclusion of at least 2.0 g kg-1 CRP in the diet of laying decreased Escherichia coli enumerations in the ileal content (P < 0.01) and improved villus height, crypt depth and goblet cell numbers (P < 0.05). An improvement in the productive performance of laying hens fed high-energy diets might be associated with decreasing health indices and product quality, which could potentially be amended by nutritional modifications such as incorporating medicinal herbs in the feed. © 2016 Society of Chemical Industry.

Dietary cholesterol and egg yolk should be avoided by patients at risk of vascular disease.

Recent recommendations that limits to dietary cholesterol be dropped were probably heavily influenced by propaganda from the egg industry. After conviction for false advertising, the industry has spent hundreds of millions of dollars to convince the public, physicians, and policy makers that dietary cholesterol and egg yolk are harmless. However, there are good reasons for longstanding recommendations that dietary cholesterol be limited to <200 mg/ day in persons at risk of vascular disease. It is seldom understood that this essentially means all people in developed countries who expect to attain an advanced age. There is abundant evidence that dietary cholesterol increases cardiovascular risk. The misdirection of the egg industry focuses on fasting levels of LDL cholesterol, which are only raised by ~ 10% by consumption of egg yolks. However, the main effect of diet is on the post-prandial state: for ~ 4 hours after a high fat/high cholesterol meal, there is oxidative stress, endothelial dysfunction, and arterial inflammation. One large (65 g) egg yolk contains 237 mg of cholesterol, well above the recommended limit-nearly as much as a 12-ounce hamburger. Besides the very high cholesterol content of egg yolk, the phosphatidylcholine in egg yolk leads, via action of the intestinal microbiome, to production of trimethylamine n-oxide (TMAO), which causes atherosclerosis in animal models. Levels of TMAO in the top quartile after a test dose of two egg yolks were associated with a 2.5-fold increase in the 3-year risk of stroke, death, or myocardial infarction among patients referred for coronary angiography. Persons at risk of cardiovascular disease should limit their intake of cholesterol and egg yolk.

Effects of rice bran on performance, egg quality, oxidative status, yolk fatty acid composition, and fatty acid metabolism-related gene expression in laying ducks

The study was designed to evaluate the effects of different dietary levels of rice bran (RB) in laying duck diets on performance, egg quality, oxidation status, egg yolk fatty acid composition, and hepatic expression of fatty acid metabolism-related genes. Longyan females (1080) with similar BW at 19 wk of age were randomly assigned to 6 dietary treatments, each consisting of 6 replicates of 30 birds. The basal diet (I) was a typical corn-soybean ration while the experimental diets (II to VI) substituted RB for corn and wheat bran and a small reduction of soybean meal. The level of substitution in diets (II to VI) was 6%, 12%, 18%, 24%, and 30%, respectively. The experiment lasted for 12 wks. Average egg weight and daily egg mass decreased linearly as the level of RB inclusion increased (P < 0.001) and feed conversion ratio linearly increased (P < 0.001). The proportions of C14:0 and C18:0 and total saturated fatty acids (SFA) in egg yolk linearly decreased with increasing RB, and many of the key polyunsaturated fatty acids (PUFA), like C18:2 n-6 and C18:3 n-3, linearly increased (P < 0.001), but not those of C20:5 n-3 and C22:6 n-3. There were linear decreases (P < 0.001) in hepatic abundance of FAS and SREBP1 transcripts, with a substantial reduction to about 30% those of ducks fed the control diet; there were no treatment effects on productive performance, eggshell thickness, strength, Haugh unit, antioxidation status, and egg yolk cholesterol or triglyceride content (P > 0.05). In conclusion, the current study suggests that ducks from 19 to 31 wk could be fed diets with up to about 18% RB without effect on the number of eggs produced, egg quality, and oxidative status. Increasing amounts of RB linearly increased egg yolk concentrations of key fatty acids like C18:2 n-6 and C18:3 n-3 and decreased the hepatic abundance of FAS and SREBP-1 transcripts.

Dietary supplementation of Echinacea purpurea powder improved performance, serum lipid profile, and yolk oxidative stability in laying hens

ABSTRACTThe present study aimed to investigate the effect of supplemental Echinacea purpurea (EP) powder on performance, serum metabolites, and yolk stability in laying hens. A total of 150 Hy-Line W-36 Leghorn laying hens, 43-wk of age, were randomly assigned into the five replicate cages for each of the five experimental diets based on a completely randomized design. Dietary treatments included different levels (0, 2.5, 5, 7.5, and 10 g/kg of diet) of EP powder, which were fed to the birds during a 70-d feeding trial. Results showed that dietary addition of EP powder caused significant (P < .05) increases in egg production during both 35-d periods and increased egg mass during the second 35-d period. A significant (P < .05) increase in secondary antibody response against sheep red blood cells was observed in groups receiving EP powder. Dietary supplementation of EP powder decreased (P < .05) yolk cholesterol and malondialdehyde concentrations. Moreover, supplemental EP decreased (P < .01) serum concentrations of triglyceride and cholesterol during the first 35-d, and resulted in increases (P < .05) in serum high-density lipoproteins during both 35-d periods. From the present findings, it can be concluded that dietary supplementation with at least 7.5 g/kg EP powder could improve egg production and decrease yolk cholesterol content. In addition, yolk oxidative stability could be improved as the result of EP supplementation of laying diets.

Production of Bio-omega-3 eggs through the supplementation of extruded flaxseed meal in hen diet.

BackgroundThe full-fat flaxseed meal has obtained relatively new flourished concept as staple chicken feedstuff for the production of designer eggs. However, unprocessed flaxseed also encloses well documented anti-nutritional factors which are associated with growth depression of laying hens. The present research work was carried out to evaluate the impact of full-fat extruded flaxseed meal supplemented diets on productivity performance of hens and production of modified ω-3 fatty acids-enriched eggs.MethodsThe full-fat flaxseed meal was extruded at barrel exit temperature (140 °C), screw speed (160 rpm) and feed rate (25 kg/h) for reduction of anti-nutritional compounds. One hundred and sixty, Babcock hens (age 24 weeks old) were selected at random from a large flock and ten hens were placed in each of 16 wire-mesh pens. The experimental diets prepared by supplementation of extruded flaxseed at 10 %, 20 % and 30 % level were fed to hens along with control.ResultsThe extruded flaxseed contained 86 % and 76 % less hydrocyanic compounds and tannin, respectively than the initial material. The hens fed with control diet consumed more feed, possessed heavy body weight and showed higher egg production as compared to hens fed on extruded flaxseed supplemented diets. The loss in body weight and egg production was recorded less for hens fed on 10 % extruded flaxseed supplemented diets as compared to those fed on 30 % extruded flaxseed supplemented diets. None of the experimental diets resulted in significant increase or decrease the total lipids and cholesterol content in egg yolk of hens. The extruded flaxseed supplemented diets resulted in a significant improvement of α-linolenic and docosahexaenoic acid in egg yolk with a concomitant reduction in arachidonic acid. The sensory scores were assigned higher to control eggs. Increasing level of extruded flaxseed in experimental diets decreased the scores for all sensory attributes of eggs.ConclusionThe present study suggested that extruded flaxseed meal up to 20 % can be supplemented in the diets of hens for maximum deposition of α-linolenic acid and docosahexaenoic acid in egg yolk with acceptable detrimental effects on egg traits.

Technological Strategies for the Development of Egg-Derived Products with Reduced Content of Cholesterol

Four different strategies were employed to obtain egg-derived products in form of sticks with a reduced cholesterol content (use of β-cyclodextrins, extraction of egg-yolk granules, bioconversion of cholesterol by cholesterol oxidase, and use of chitosan as a chelating agent). The developed products were analyzed and compared to conventional egg-derived products for their proximate composition, cholesterol content, color, and consumer acceptability. Additionally, the lipid oxidation and surface color stability of modified and conventional egg-derived products were investigated during 30 days of frozen storage. The results obtained showed reductions in the cholesterol content of egg-derived yolks ranging from 27.11 % (chitosan addition in a range 1:1) to 87.54 % (β-cyclodextrins added directly). Lipid oxidation determinations revealed that no significant increases were found in any of the developed yolks with respect to control ones. In fact, chitosan-added products (in a range 2:1) and egg-derived products elaborated with yolk granules showed significantly lower lipid oxidation than control ones after frozen storage. Consumer acceptability parameters did not reveal significant differences between chitosan-added egg-derived products with respect to the control ones, with the only exception of a slight difference in odor (5.57 in chitosan-added product vs 5.14 in control product). Considering all the results obtained, egg-derived yolk that was chelated by chitosan contained the best balance out of the four methodologies employed, considering price, the ease of industrial application, and the minor changes in color and consumer acceptability. The final reduction of cholesterol content using this method was about 50 %.

Effect of Fennel (Foeniculum Vulgare Mill.) Used as a Feed Additive on The Egg Quality of Laying Hens Under Heat Stress

In this study, one hundred and twenty 40-wk-old White Leghorn laying hens were submitted to two different thermal conditions (24° C vs. 34° C) and were fed three levels (0, 10, or and 20 g/kg of diet)of fennel fruits (Foeniculum vulgare Mill.) as a feed additive in. This study was carried out according to a factorial design consisting of two temperatures and three fennel levels with five 5 replicates each (n = 2 × 3 × 5). Performance, egg production, egg quality, and oxidative product levels (malondialdehyde, MDA, and carbonyl) in the eggs were measured before and after heat exposure. The results showed that the tested temperatures did not affect egg production (p>0.05), but the production of eggs with broken shell and feed intake were affected by heat stress (p<0.05). The different temperatures also affected egg quality (p<0.05), reducing egg weight (EW), eggshell thickness (EST), eggshell strength (ESS), Haugh units (HU), albumen height (AH), and albumen weight (AW). At the high environmental temperature, MDA and carbonyl egg contents increased (p<0.05), while fennel consumption reduced the values of both parameters. Heat stress had no effect on yolk cholesterol levels (p>0.05), but increased yolk triglyceride levels. Hens that consumed fennel presented lower yolk cholesterol and triglyceride levels (p<0.05). In general, fennel fruit influenced egg yolk cholesterol and triglyceride contents, and because of its antioxidant properties, it may alleviate the adverse effects of heat stress on laying hens.

THE MODULATION OF PERFORMANCE, CHOLESTEROL CONTENT AND IMMUNE RESPONSE INDUCED BY SACCHAROMYCES CEREVISIAE IN LAYING HENS

This study was conducted to evaluate the effect of Saccharomyces cerevisiae supplementation of a commercial layer diet on the laying performance, blood lipid profile, liver and yolk cholesterol content, and immune response during 8-week period. A total of 180 Hy-line Brown laying hens of 40 wk of age were allocated to 4 dietary treatments, where every 45 hens were divided into three replicates. The basal diet was supplemented with Saccharomyces cerevisiae at the levels of 0.0, 0.2, 0.4, and 0.6%. Results showed that the highest egg number and egg weight were observed with 0.6% Saccharomyces cerevisiae supplement. Supplementing diets with Saccharomyces cerevisiae at all levels (0.2, 0.4, and 0.6%) significantly (P˂0.05) increased egg mass, antibody production, cell-mediated immune response, and reduced feed consumption, plasma cholesterol, LDL-cholesterol levels and liver cholesterol concentration. Furthermore, hens fed diets supplemented with 0.4 and 0.6% Saccharomyces cerevisiae showed significant enhancement of feed conversion ratio, an increase of plasma HDL-cholesterol and a reduction of both yolk cholesterol concentration and Heterophil:lymphocyte (H/L) ratio. In conclusion, Saccharomyces cerevisiae could be used to enhance production performance and immune response, and control cholesterol content of plasma, yolk and liver.

A shift in erythrocyte histone H1 complement following selection in quail (Coturnix japonica)

This work was aimed at comparing distribution of isoforms for polymorphic histone H1 variants H1.b and H1.z and variably abundant histone H1.d subtype between quail ( Coturnix japonica ) population selected for a high egg yolk cholesterol content and the control birds. The isoforms of histone H1.b (H1.b1, H1.b2) and histone H1.z (H1.z1, H1.z2) differed in their apparent molecular weights judging from their differential migration rates in one- and two-dimensional SDS-polyacrylamide gels. Stained histone H1.d bands and spots in one-dimensional acetic acid-urea and two-dimensional SDS-polyacrylamide gel patterns, respectively, exhibited differential intensities among quail individuals. Histone H1.d phenotypes with high (d h ), intermediate (d h d l ), and low (d l ) amount of protein, displaying a small within-phenotype variability of the protein band intensities (coefficients of band variation below a threshold value of 0.25) were shown to be inherited in a Mendelian fashion with two alleles at a locus contributing to the band intensity. The frequencies of histone H1 alleles at loci H1.b (χ 2 = 13.32, d.f. = 1, P < 0.001), H1.z (χ 2 = 21.84, d.f. = 1, P < 0.001), and H1.d (χ 2 = 8.98, d.f. = 1, P < 0.01) were found to be statistically significant among the control and selected population. In general, a moderate degree of genetic divergence (F ST equal to 0.07 and 0.1 at loci H1.b and H1.z, respectively) was observed among the control and selected quail populations. Selection may directly or indirectly affect the complement of H1 histones because of their presumably differential interactions with DNA and/or DNA-associated proteins resulting in alterations in the chromatin function.