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The emergence of SARS-CoV-2 in late 2019 initiated a global pandemic, which led to a need for effective therapeutics and diagnostic tools, including virus-specific antibodies. Here, we investigate different antigen preparations to produce SARS-CoV-2-specific and virus-neutralizing antibodies in chickens (n = 3/antigen) and rabbits (n = 2/antigen), exploring, in particular, egg yolk for large-scale production of immunoglobulin Y (IgY). Reactivity profiles of IgY preparations from chicken sera and yolk and rabbit sera were tested in parallel. We compared three types of antigens based on ancestral SARS-CoV-2: an inactivated whole-virus preparation, an S1 spike-protein subunit (S1 antigen) and a receptor-binding domain (RBD antigen, amino acids 319–519) coated on lumazine synthase (LS) particles using SpyCather/SpyTag technology. The RBD antigen proved to be the most efficient immunogen, and the resulting chicken IgY antibodies derived from serum or yolk, displayed strong reactivity with ELISA and indirect immunofluorescence and broad neutralizing activity against SARS-CoV-2 variants, including Omicron BA.1 and BA.5. Preliminary in vivo studies using RBD–lumazine synthase yolk preparations in a hamster model showed that local application was well tolerated and not harmful. However, despite the in vitro neutralizing capacity, this antibody preparation did not show protective effect. Further studies on galenic properties seem to be necessary. The RBD–lumazine antigen proved to be suitable for producing SARS-CoV-2 specific antibodies that can be applied to such therapeutic approaches and as reference reagents for SARS-CoV-2 diagnostics, including virus neutralization assays. [ABSTRACT FROM AUTHOR]

1. The study analysed the content of fatty acids in the lipids of the yolk and yolk sac of hatching eggs obtained from geese in four reproductive flocks and three laying periods at different incubation dates. 2. A total of 1080 hatching eggs were used in the study (90 eggs from each age group in three laying periods). The geese were kept on one farm under the same conditions. 3. On days 0, 16, 22, and 28 of incubation, the yolk/yolk sac was sampled. Saturated and unsaturated (mono- and poly-) fatty acids were determined, including myristic acid, palmitic acid, palmitoleic acid, margaric acid, stearic acid, oleic acid, linoleic acid, α-linolenic acid, behenic acid, eicosapentaenoic acid. The ratio of unsaturated to saturated fatty acids was calculated. 4. Embryo fatty acid utilisation in eggs from different age groups of geese was similar. The fatty acid profile depended mostly on the laying period. The different proportions of fatty acids in the yolk during incubation indicated changes in the activity of various enzymatic processes in the membrane of the yolk sac of embryos from the beginning and at the end of the laying period. 5. When analysing the interactions between the age of the parent flock and the laying period, the most significant effect on the fatty acid composition was found in fresh eggs. On d 16 of lay the myristic, stearic, linoleic, and behenic acids and PUFA; on d 22 of lay linolenic acid, and on day 28th palmitoleic and margaric acids were involved in this interaction. [ABSTRACT FROM AUTHOR]

Phosvitin is the most phosphorylated naturally occurring protein and it is concentrated in the granular fraction of egg yolk. It has interesting antioxidant and cation chelating properties that can be used to preserve food and cosmetics, but its industrial application is limited as its separation relies on the use of organic solvents and chromatographic techniques, which are expensive and difficult to assimilate in a continuous procedure. In this study, we propose a new phosvitin separation process using substances legally accepted for use in the food industry (NaCl and HCl), employing egg yolk granules as raw material. In this case, the NaCl concentration and the pH of the solution of granules were screened in order to obtain a phosvitin-rich supernatant after centrifugation. Additionally, two new processes were proposed to purify this phosvitin-rich solution. The first was the precipitation of impurities during the desalting stage at optimized pH values. The second was ultrafiltration under selected pH value conditions. A low nitrogen/phosphorous (N/P) atomic ratio is considered a quality parameter, with 3.6 ± 0.2 being the value of the phosvitin-rich supernatant. The two purification processes provided highly purified phosvitin with a similar N/P value of 2.5 ± 0.1. The high level of purification of the phosvitin was confirmed using electrophoresis and ion-exchange chromatography. In particular, the purified phosvitin obtained via ultrafiltration is already desalted and membrane technology is more easily scalable than that based on chromatography, thus facilitating the industrial separation and commercialization of the phosvitin. [ABSTRACT FROM AUTHOR]

Simple Summary: Several studies have reported the absolute weight and concentration of minerals in hen and turkey yolks during incubation. However, there is limited information about some minerals in goose egg yolks during the incubation period. The incubation period of goose chicks is 30 days, and the chicks emerge after this period. As a result of mineral transfer between the ovary, yolk, albumin and shell, egg yolk mineral content increases during incubation. We studied whether the mineral reserves of goose egg yolk changed, and whether mineral deficiency in goose embryos resulted in skeletal, cardiovascular and immune weakness. According to the present study, except for calcium, the content of all the examined minerals decreases during incubation. This study evaluated the changes in calcium (Ca), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), sodium (Na), phosphorus (P), strontium (Sr) and zinc (Zn) values in goose egg yolk during the incubation period. This study was conducted on a completely random selection using 200 fertile eggs from a local flock of geese. A selection of 30 fertile eggs were randomly sampled on days 0, 9.5, 19.5, 25 and 30 of incubation (total: 150 eggs), and the yolks of 5 eggs in each replicate were mixed together and considered as one replicate (six replicates in each incubation period). The mineral content of the yolks was measured using the inductively coupled plasma (ICP) spectroscopy method. The results of this study show that, during the incubation of goose eggs from 0 to 30 days of embryo growth, except for Ca, the yolk content (absolute weight) of all the measured minerals, including Cu, Fe, K, Mg, Mn, Na, P, Sr and Zn, on day 30 of incubation were statistically significantly lower than on day 0 of incubation. Additionally, the yolk concentrations of Fe, K, Mg, Na, P and Zn declined, the yolk concentrations of Ca and Sr increased, and the yolk concentrations of Cu and Mn were unchanged on day 30 compared to the first day of incubation. The results of the current study demonstrate that goose egg yolks' mineral concentrations change in absolute value during the incubation period, which could be the basis for further studies on chick feeding during the embryonic and post-embryonic phases. [ABSTRACT FROM AUTHOR]

Reproductive modes of vertebrates are classified into two major embryonic nutritional types: yolk deposits (i.e. lecithotrophy) and maternal investment (i.e. matrotrophy). Vitellogenin (VTG), a major egg yolk protein synthesized in the female liver, is one of the molecules relevant to the lecithotrophy-to-matrotrophy shift in bony vertebrates. In mammals, all VTG genes are lost following the lecithotrophy-to-matrotrophy shift, and it remains to be elucidated whether the lecithotrophy-to-matrotrophy shift in nonmammalians is also associated with VTG repertoire modification. In this study, we focused on chondrichthyans (cartilaginous fishes)—a vertebrate clade that underwent multiple lecithotrophy-to-matrotrophy shifts. For an exhaustive search of homologs, we performed tissue-by-tissue transcriptome sequencing for two viviparous chondrichthyans, the frilled shark Chlamydoselachus anguineus and the spotless smooth-hound Mustelus griseus , and inferred the molecular phylogeny of VTG and its receptor very low-density lipoprotein receptor (VLDLR), across diverse vertebrates. As a result, we identified either three or four VTG orthologs in chondrichthyans including viviparous species. We also showed that chondrichthyans had two additional VLDLR orthologs previously unrecognized in their unique lineage (designated as VLDLRc2 and VLDLRc3). Notably, VTG gene expression patterns differed in the species studied depending on their reproductive mode; VTGs are broadly expressed in multiple tissues, including the uterus, in the two viviparous sharks, and in addition to the liver. This finding suggests that the chondrichthyans VTGs do not only function as the yolk nutrient but also as the matrotrophic factor. Altogether, our study indicates that the lecithotrophy-to-matrotrophy shift in chondrichthyans was achieved through a distinct evolutionary process from mammals. [ABSTRACT FROM AUTHOR]

In recent years, the market share for cage-free eggs has gradually increased. Because commercially available cage-free eggs are often produced not only by several housing systems but also with different feed crude protein (CP) levels, there are combined effects of feed and housing systems between cage-free and cage eggs. Therefore, using field data, this study aimed to determine the combined effects of feed and housing systems on egg traits and yolk and albumen amino acids in table eggs. Brown layers (n = 40) at the middle laying stage under two feed and housing systems (cage, CP 15.5% diet; barn, CP 17.0% diet) were used. One-way analysis of variance and Pearson's correlation analysis were used to evaluate 10 egg traits, 19 yolk amino acid traits, and 20 albumen amino acid traits. We observed significant effects of feed and housing on two egg traits (yolk weight and eggshell color redness), 16 yolk amino acids (Asp, Glu, Asn, Ser, Gln, His, Arg, Thr, Ala, Tyr, Met, Cys, Ile, Leu, Phe, and Lys), and 14 albumen amino acids (Asp, Asn, Ser, Gln, Gly, His, Arg, Thr, Ala, Val, Met, Cys, Ile, and Leu). This study revealed that eggs from the barn system (CP 17.0%) contained higher levels of free amino acids in 15 yolk and nine albumen amino acid traits. Phenotypic correlations among the 49 egg traits indicated similar correlation patterns in both systems, which implies that the balance of free amino acid content in yolk and albumen is similar in each system. Although some potential confounding factors may be present for comparing egg content between cage (CP 15.5%) and barn (CP 17.0%) systems, this study suggests that commercially available cage-free eggs may be different from cage eggs not only in external egg traits but also yolk and albumen amino acid traits. [ABSTRACT FROM AUTHOR]

In this study, sonication with mild heat treatment was used to reduce the E. coli count in inoculated liquid whole egg, egg yolk and albumen. Ultrasonic equipment (20/40 kHz, 180/300 W) has been used for 30/60 min with a 55 °C water bath. The combination of sonication and low-heat treatment was able to reduce the concentration of E. coli from 5-log CFU × mL−1 below 10 CFU × mL−1 at 300 W, 40 kHz and 60 min of sonication in liquid egg products. The 60 min treatment was able to reduce the E. coli concentration below 10 CFU × mL−1 in the case of egg yolk regardless of the applied frequency, absorbed power or applied energy dose. The 30 min treatment of sonication and heating was able to reduce significantly the number of E. coli in the egg products, as well. Our results showed that sonication with mild heat treatment can be a useful technique to decrease the number of microorganisms in liquid egg products to a very low level. Near-infrared spectroscopy was used to investigate structural changes in the samples, induced by the combined treatment. Principal component analysis showed that this method can alter the C-H, C-N, -OH and -NH bonds in these egg products. [ABSTRACT FROM AUTHOR]

Simple Summary: Despite the regional preferences for quail eggs and meat, and the main production being found in Asian countries, the popularity of quail raising has increased and their production has been introduced in many other countries, including the Baltics. A wide distribution around the world encouraged genetic divergence among Japanese quail populations, the formation of different breeds and lines as well as their research. The Estonian quail, a breed developed in Estonia, has also spread in Lithuania. This study aimed to evaluate yolk and albumen colour, as well as the nutritional value of yolk lipids in Estonian quail eggs using diets supplemented with cakes from local oil corns (rapeseed, hemp and camelina seeds). The diet affected the colour as well as the cholesterol content and fatty acid composition of the yolk. All quail groups demonstrated the high lightness (L*) and yellowness (b*) of the yolk; however, the negative value of parameter a*, instead of being red, showed a greenish colour. The highest proportions of total saturated (SFAs) and polyunsaturated (PUFAs) fatty acids as well as the lowest monounsaturated fatty acids (MUFAs) were found in the yolk lipids of the quail which was fed a mixture supplemented with hemp cake. The lowest and most favourable n-6/n-3 ratio was demonstrated by the quail fed the diet supplemented with camelina. However, the lowest yolk cholesterol content was demonstrated by the quail fed the diet supplemented with rapeseed cake. The aim of this study was to investigate the effects of supplementing commercial diets with rapeseed, hempseed and camelina seed cakes on the yolk and albumen colour and nutritional value of yolk lipids in Estonian quail eggs. A total of 585 eggs were used to evaluate egg weight, yolk and albumen pH and colour, proximate yolk composition, cholesterol content and fatty acid composition in the yolk lipids of three Estonian quail groups each fed a diet supplemented with 10% rapeseed, hemp or camelina seed cakes. The higher (p < 0.01 and p < 0.05, respectively) lightness (L*) of the yolk was detected in the group of quail fed the diet supplemented with rapeseed and camelina cakes compared to the hempseed addition. Meanwhile, the albumen lightness in the rapeseed group was higher (p < 0.01) in comparison to the camelina group. A lower (p < 0.001) yolk negative a* value was estimated in the hemp group than in the groups fed rapeseed and camelina seed cake supplements, while the rapeseed group demonstrated lower (p < 0.001) albumen yellowness (b*) and colour saturation (C) in comparison to the other groups. The highest and lowest proportions of total saturated (SFAs)and monounsaturated (MUFAs) fatty acids, respectively, were found in the yolk lipids of quails fed a mixture supplemented by hemp cake. A higher (p < 0.05) proportion of polyunsaturated fatty acids (PUFAs) was only found in the hemp group compared to the camelina group. The highest and lowest (p < 0.001) n-6/n-3 PUFA ratios were found in the yolk lipids of quail receiving mixtures supplemented with rapeseed and camelina cakes, respectively. The yolk of the quail from the rapeseed group showed more favourable lower and higher (p < 0.01 and p < 0.05, respectively) atherogenic index (AI) and hypocholesterolemic/hypercholesterolemic (h/H) ratio compared to the hemp and camelina groups. The lower yolk cholesterol content was found in the eggs of the quail fed the diet supplemented with rapeseed cake compared to the eggs of the quail which were fed the diets containing more n-3 PUFAs from the addition of hemp and camelina cakes (p < 0.05 and p < 0.01, respectively). [ABSTRACT FROM AUTHOR]

There is increasing interest in using grass-fed beef (GFB) by-products to augment the nutrient profile of eggs among local pasture-raising systems in the US. The objective of this study was to characterize egg yolk fatty acid and antioxidant profiles using eggs from pasture-raised hens fed a corn- and soy-free diet and supplemented with GFB suet and liver compared to eggs from pasture-raised hens fed a corn and soy layer hen feed and commercially obtained cage-free eggs. The egg yolk vitamin and mineral profile was also assessed by a commercial laboratory. Both pasture-raised groups had twice as much carotenoid content, three times as much omega-3 fatty acid content, and a 5–10 times lower omega-6:omega-3 fatty acid ratio compared to the cage-free eggs (p < 0.001). Eggs from hens fed a corn- and soy-free feed and GFB by-products had half as much omega-6 fatty acid content and five times more conjugated linoleic acid, three times more odd-chain fatty acid, and 6–70 times more branched-chain fatty acid content (p < 0.001). Feeding pasture-raised hens GFB suet and liver reduces agricultural waste while producing improved egg products for consumers, but further research is needed to quantify optimal supplementation levels and the efficacy of corn- and soy-free diets. [ABSTRACT FROM AUTHOR]

Issues related to food authenticity, traceability, and fraud have increased in recent decades as a consequence of the deliberate and intentional substitution, addition, tampering, or misrepresentation of food ingredients, where false or misleading statements are made about a product for economic gains. This study aimed to evaluate the ability of a portable NIR instrument to classify egg samples sourced from different provenances or production systems (e.g., cage and free-range) in Australia. Whole egg samples (n: 100) were purchased from local supermarkets where the label in each of the packages was used as identification of the layers' feeding system as per the Australian legislation and standards. The spectra of the albumin and yolk were collected using a portable NIR spectrophotometer (950–1600 nm). Principal component analysis (PCA) and linear discriminant analysis (LDA) were used to analyze the NIR data. The results obtained in this study showed how the combination of chemometrics and NIR spectroscopy allowed for the classification of egg albumin and yolk samples according to the system of production (cage and free range). The proposed method is simple, fast, environmentally friendly and avoids laborious sample pre-treatment, and is expected to become an alternative to commonly used techniques for egg quality assessment. [ABSTRACT FROM AUTHOR]

Portulaca oleracea is a widespread herbaceous plant particularly rich in polyunsaturated fatty acids (PUFA), antioxidant compounds and characterised by a healthy omega-6/omega-3 ratio. The focus of this research was to evaluate the effects of Portulaca oleracea supplementation to the diet of laying hens on productive performance, egg physical traits, fatty acid composition and cholesterol content. Twenty-six 24-week-old Warren strain layers were randomly assigned to two different groups of 18 and eight birds, respectively: one group received a commercial diet (C) whereas the other group was given the same control diet supplemented with 20% of dried Portulaca oleracea (PO). Hens were fed for 21 days. Feed and water were provided ad libitum. The poor palatability of the PO diet compromised the optimisation of the productive performance, with a significant reduction of the oviposition efficiency (0.69 vs 0.88 for PO and C, respectively; P < 0.05) and egg physical traits. Considering the egg nutritional traits, dietary PO significantly decreased the yolk proportion of saturated fatty acid (43.0% vs 44.1%, P < 0.05), while it increased the content of PUFA (19.4% vs 17.8%, P < 0.001), and within the latter, both omega-6 and omega-3 proportion significantly increased in comparison with C group (16.4% vs 17.6%, P < 0.001 and 1.46% vs 1.80%, P < 0.001, for n-6 and n-3, respectively). This resulted in an improvement of the omega-6/omega-3 ratio (10.4 vs 11.3 for PO and C, respectively; P < 0.05). Egg yolk cholesterol content did not vary between dietary treatments. It could be concluded that the use of Portulaca oleracea for producing omega-3-enriched eggs is feasible once the problem of palatability has been overcome and the energy requirements of the hens have been covered. [ABSTRACT FROM AUTHOR]

The relevance of this study is conditioned upon the active introduction of prebiotic preparations into the practice of feeding poultry and the need to determine the impact of their use on quantitative and qualitative indicators of productivity. In this regard, this study is aimed at determining the effect of the introduction of the prebiotic preparation Actigen in the diet of laying hens on their level of productivity and morphological parameters of eggs. Using an integrated approach, the level of egg productivity of chickens was investigated for the introduction of the preparation into the mixed feed in the amount of 500 g/t for 6 weeks. Assessment of poultry at 52 weeks of life indicates a slightly higher level of egg production of chickens of the experimental group – 198.6 pcs against 196.2 pcs in the control group (the difference is 1.22%) and the safety of livestock – 97.50% against 97.00% in the control group. It was found that the mass of eggs obtained from chickens of the experimental group was higher by 1.09 g (p<0.05). A lower level of variation (Cv) of the “egg mass” trait of the poultry of the experimental group (3.05%) than in the control group (3.51%) is positive, and indirectly indicates the level of uniformity of the herd in live weight. It was established that the weight of egg white and yolk of hens in the experimental group was 1.04 g and 0.37 g higher, respectively, than in the control group. The difference between groups is not statistically significant, but it shows the direction of their changes. In the eggs of the experimental group, the large diameter of the egg white was smaller compared to the control group by 1.93%, and the small diameter by 3.56%. The height of the dense layer of white and yolk, which are objective indicators of egg quality, were greater in the experimental group (p<0.001) compared to the control group, which is positive, this difference was 21.54% and 20.00%, respectively. According to the indicators of the energy value of eggs, no substantial differences were found between the experimental groups. The obtained data (increase in the level of egg production of poultry, preservation of livestock, egg weight, improvement of egg quality indicators of chickens of the experimental group) indicate a positive effect of the introduction of the prebiotic preparation Actigen on the level of egg productivity of poultry. The materials of this paper are of practical value for the work of poultry enterprises specialising in the production of food-grade chicken eggs. [ABSTRACT FROM AUTHOR]

PurposeTo investigate the tissue-like multiexponential T2 signal decays in avian eggs.MethodsTransverse relaxation studies of raw, soft-boiled and hard-boiled eggs were performed at 3 Tesla using a three-dimensional Carr-Purcell-Meiboom-Gill imaging sequence. Signal decays over a TE range of 11 to 354 ms were fitted assuming single- and multicomponent signal decays with up to three separately decaying components. Fat saturation was used to facilitate spectral assignment of observed decay components.ResultsEgg white, yolk and the centrally located latebra all demonstrate nonmonoexponential T2 decays. Specifically, egg white exhibits two-component decays with intermediate and long T2 times. Meanwhile, yolk and latebra are generally best characterized with triexponential decays, with short, intermediate and very long T2 decay times. Fat saturation revealed that the intermediate component of yolk could be attributed to lipids. Cooking of the egg profoundly altered the decay curves.ConclusionAvian egg T2 decay curves cover a wide range of decay times. Observed T2 components in yolk and latebra as short as 10 ms, may prove valuable for testing clinical sequences designed to measure short T2 components, such as myelin-associated water in the brain. Thus we propose that the egg can be a versatile and widely available MR transverse relaxation phantom.

Research in other species suggests that the source of embryonic calcium (Ca) and phosphorus (P) for Crocodylus niloticus is likely yolk and shell. Using inductively coupled plasma optical emission spectroscopy (ICP-OES), the Ca and P concentration and content of 30 fertile eggs was determined within 10 days prior to anticipated hatching, and compared with those of size-matched unbanded eggs (eggs that failed to form an opaque band around the lesser circumference, indicative of presumed infertility). Shell contained the highest Ca concentration and content, followed by the foetus, followed by the intra-abdominal yolk. Foetal tissue had the highest P concentration and content, followed by intra-abdominal yolk. The Ca and P concentration of intra-abdominal yolk of foetuses in fertile eggs varied more widely than did the yolk of unbanded eggs, based on coefficient of variation. Ca concentration of fertile egg yolk was in some cases found to exceed that of the yolk of unbanded eggs, suggesting that Ca is stored there after being removed from the shell, however, yolk Ca content was consistently lower in fertile than in unbanded eggs, indicating net yolk Ca depletion. Yolk P concentration and content of fertile eggs was consistently lower than that of unbanded eggs, suggesting a net depletion of yolk P reserves, without replenishment. The Nile crocodile appears to follow the classic archosaurian pattern of Ca mobilisation, whereby the shell supplies the majority of foetal Ca, but the intra-abdominal yolk contains substantial Ca reserves for use by the hatchling. This study provides clinicians and researchers with information on sample collection and analysis of Nile crocodile egg and foetal tissue, provides baseline descriptive data on Ca and P concentration and content, discusses the effect of potential covariates on Ca and P concentration and content, and discusses the movement of Ca and P from reserves within the egg to the developing foetus. [ABSTRACT FROM AUTHOR]

Aqueous film–forming foams (AFFFs) are used in firefighting and are sources of per‐ and polyfluoroalkyl substances (PFAS) to the environment through surface runoff and groundwater contamination at defense and transportation sites. Little is known regarding the toxicity and bioaccumulation of newer AFFF formulations containing novel PFAS. To mimic maternal transfer of PFAS, prefertilization rainbow trout eggs were exposed to three PFAS using novel methodologies. Batches of unfertilized oocytes were exposed for 3 h to 0, 0.01, 0.1, 1, or 10 µg/ml separately to perfluorooctanoic acid, perfluorohexanoic acid, or perfluorooctanesulfonic acid in either coelomic fluid or Cortland's solution. After exposure, the gametes were fertilized and rinsed with dechlorinated water. Egg yolk was aspirated from a subset of fertilized eggs for PFAS quantification. Each PFAS was detected in yolks of eggs exposed to the respective PFAS, and yolk concentrations were directly proportional to concentrations in aqueous media to which they were exposed. Exposure in coelomic fluid or Cortland's solution resulted in similar concentrations of PFAS in egg yolks. Ratios of PFAS concentrations in oocytes to concentrations in exposure media (oocyte fluid ratios) were <0.99 when exposed from 0.01 to 10 µg/ml and <0.45 when exposed from 0.1 to 10 µg/ml for both media and all three PFAS, demonstrating that the water solubility of the chemicals was relatively great. Prefertilization exposure of eggs effectively introduced PFAS into unfertilized egg yolk. This method provided a means of mimicking maternal transfer to evaluate toxicity to developing embryos from an early stage. This method is more rapid and efficient than injection of individual fertilized eggs and avoids trauma from inserting needles into eggs. Environ Toxicol Chem 2021;40:3159–3165. © 2021 SETAC [ABSTRACT FROM AUTHOR]

In this experiment, 320 laying hens of Hy-Line W-36 strain were used in a 2 x 2 x 2 factorial design (eight treatments and eight birds in each pen). The treatments were 0 and 400 mg/kg iron salt, 0 and 450 mg/kg iodide, and 0 and 0.1 mg/kg vitamin B12. There were five replicates of each treatment combination and the birds were from 26 to 39 weeks old. The interaction of iron salt and iodide, the use of 450 mg/kg iodide and 0 levels of iron salt increased the iodide content of yolks. In the treatments with 400 mg/kg of iron salt combined with iodide and with 400 mg/kg of iron salt with 0 levels of iodine salt this caused a sharp decrease in the iodide content of the yolk. In the interaction of treatments containing iron salt and vitamin B12, the lowest amount of cobalt and the highest level of Iodide were observed at the 0 levels of both supplements, whereas the combined use of iron salt and vitamin B12 increased the level of cobalt and decreased the yolk iodine content. In the three-way effects between these salts, yolk iron and cobalt content increased, and the highest amount of Iodine was observed in the third treatment (without vitamin B12 and iron). Overall the use of iron salt, iodine, and vitamin B12 could improve the performance of hens and the composition of egg yolk. [ABSTRACT FROM AUTHOR]

The aim of the study was to evaluate the transfer of bioactive compounds from sea buckthorn meal (SBM) supplement to eggs and the effect on lipid quality and peroxidation process. Thirty-two weeks old TETRA SL laying hens were allocated to two dietary treatments, 30 birds each (15 replicate pens). The control diet (C) contained a maize-soybean diet and the experimental diet contained the previous C diet with 2% of maize replaced with SBM. Thirty-six eggs from each group were collected in order to determine the quality parameters at the end of experiment. The antioxidant profile of SBM showed that the phytoadditive is a valuable source of vitamin E, xanthophylls and polyphenols. The inclusion of 2% of SBM in the experimental diet led to a more than 25% increase of vitamin E and an almost 50% increase of xanthophylls compared to the control. The markers specific to the coronary risk decreased significantly in the experimental group compared to the control, showing a beneficial effect of dietary SBM on the quality of yolk lipids. The bioactive compounds detected in egg yolk showed a significant (P < 0.05) improvement of the antioxidant profile, the rate of vitamin (A and E), carotenoid (lutein and zeaxanthin) and mineral (iron and zinc) deposition increased after dietary SBM inclusion. Regarding the lipid peroxidation parameters, the dietary SBM inclusion acted in the first phase of the lipid peroxidation process by inhibiting the formation of primary oxidation products (hydroperoxides and conjugated dienes). In conclusion, the sea buckthorn supplementation of laying hen diet improved the bioactive compound concentrations in eggs and delayed the oxidation process of yolk during storage. [ABSTRACT FROM AUTHOR]

Concentrated microwave field (CMF) is the technology for preserving liquid food products, where the preservation factor is both a nonthermal effect and a moderate thermal effect. The term "concentrated microwave field" is traditionally used in Poland and is the equivalent to "single-mode-type microwave heating". The aim of the research was to determine selected physical and rheological properties of liquid egg white, liquid yolk and liquid whole eggs (LWE) after CMF treatment. It was found that both the amount of energy supplied to the system and the intervals between CMF pulses had a statistically significant impact on the analyzed properties of liquid egg raw materials. In industrial practice, it would be recommended to use lower CMF treatment (at the level of 2.2–2.6 kJ) for the yolk, medium (3.2–3.6 kJ) for egg white and higher (4.0–4.4 kJ) for the liquid whole eggs. The "response surface" models presented in the paper may have a practical application in determining the influence of individual technological parameters on the final quality of various liquid food products. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Central European Agriculture is the property of Journal of Central European Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The objective of the current study was to evaluate increasing levels of manganese hydroxychloride (MHC) in 45-wk-old white leghorn laying hens, using yolk and shell manganese (Mn) content as a potential marker for Mn concentration. A total of 80, 45-wk-old white leghorns were assigned to 6 dietary treatments, each consisting of 14 individually caged laying hens, with the exception of the reference diet containing 10 individually caged laying hens. The experiment consisted of a reference diet that contained 70 ppm of supplemental inorganic Mn in the form of Mn oxide and 5 experimental treatments each containing 0, 15, 30, 60, and 90 ppm supplemental MHC. Experimental birds were subjected to a 21 D depletion phase in which no supplemental Mn was included in the diet; however, during this time reference fed birds were fed the control diet (70 ppm Mn). After the 21 D depletion phase, the depleted birds were fed experimental diets for a 35 D evaluation period. Yolk and shell Mn content were analyzed at the end of the depletion phase and during the experimental phase on day 5, 10, 15, 25, and 35. During the experimental phase, Mn was replenished in the yolk and shell in all experimental treatments containing supplemental Mn; however, dose and time impacted the rate of replenishment. The yolk tended to be more sensitive to variations in Mn level as increases in Mn inclusion significantly (P < 0.05) increased concentration. These data demonstrate the ability to deplete and replenish Mn, and the use of egg yolk Mn concentration as measurement for determining changes in dietary Mn. At the conclusion of the experiment at 35 D, 60 ppm of Mn hydroxychloride seemed to be adequate in replenishing Mn to the level of the reference. [ABSTRACT FROM AUTHOR]

ABSTRACTS Eggs are highly nutritious food whose high cholesterol content has been always an inconvenience due to concerns about the relationship between dietary cholesterol and atherosclerotic cardiovascular risk. As this remains uncertain, low cholesterol intake is recommended. This review deals with the techniques employed to reduce the cholesterol content in egg yolk once the egg is shelled. There are four main techniques: i) solvent extraction, ii) fractionation by centrifugation, iii) cholesterol chelates or adsorbents and iv) cholesterol biotransformation. Analyse of techniques, descriptions and recent advances are included in this review. Solvent extraction and cholesterol biotransformation allow to reduce up to 94.7% and 93.4%, respectively. However, both methods have not been scaled up due to food safety and economic reasons. Nowadays, fractionation by centrifugation and cholesterol chelates are the only feasible methods with industrial applications, obtaining up to 82% and 99%, respectively. Fractionation method can be considered the best because no substances are added. [ABSTRACT FROM AUTHOR]

Vitellogenins are a family of yolk proteins that are by far the most abundant among oviparous animals. In the model nematode Caenorhabditis elegans , the 6 vitellogenins are among the most highly expressed genes in the adult hermaphrodite intestine, which produces copious yolk to provision eggs. In this article we review what is known about the vitellogenin genes and proteins in C. elegans , in comparison with vitellogenins in other taxa. We argue that the primary purpose of abundant vitellogenesis in C. elegans is to support post-embryonic development and fertility, rather than embryogenesis, especially in harsh environments. Increasing vitellogenin provisioning underlies several post-embryonic phenotypic alterations associated with advancing maternal age, demonstrating that vitellogenins can act as an intergenerational signal mediating the influence of parental physiology on progeny. We also review what is known about vitellogenin regulation – how tissue-, sex- and stage-specificity of expression is achieved, how vitellogenins are regulated by major signaling pathways, how vitellogenin expression is affected by extra-intestinal tissues and how environmental experience affects vitellogenesis. Lastly, we speculate whether C. elegans vitellogenins may play other roles in worm physiology. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Animal & Poultry Production is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A total of 864 settable Cobb 500 eggs were used to explore changes in yolk mineral content during incubation. Eggs were individually weighed and then placed in a commercial incubator. On embryonic day (ED) 0, 6.5, 13.5, and 17.5, 36 eggs were sampled and yolk weight and mineral content were determined. The concentration of iron (Fe), phosphorus (P), and zinc (Zn) declined (P < 0.05) from ED0 to ED17.5. The concentration of calcium (Ca), magnesium (Mg), and strontium (Sr) increased (P < 0.05) from ED0 to ED17.5. The concentration of copper (Cu), potassium (K), and sodium (Na) increased initially (ED0 to ED6.5) but declined thereafter. There was no change (P > 0.05) in the concentration of yolk manganese (Mn) from ED0 to ED17.5. Substantial changes in yolk mineral concentration occur during incubation and are presumably associated with mobilization of shell reserves and flux between albumen and yolk. These data may be useful in designing in ovo interventions, optimizing meat chicken breeder premix formulation or assembly of suitable neonatal or pre-starter diets for meat chicken chicks. [ABSTRACT FROM AUTHOR]

Copyright of Al-Anbar Journal of Veterinary Sciences is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Infertile eggs from Chinese Painted quail exhibit parthenogenesis, and the 1st egg in a clutch sequence is more likely to develop a parthenogenetic embryo. Also, hens that exhibit parthenogenesis have shorter clutches and heavier egg weights. These larger eggs may be a result of the egg residing in the oviduct longer, allowing more time for the parthenote to develop. However, it is unknown which components of the egg are altered due to the parthenogenetic trait or the role of dams and sires from the parthenogenetic line of quails in these alterations. Therefore, our objective was to determine if the parthenogenetic trait in dams, sires, or both contributes to alterations in egg components, such as yolk, albumen, and shell weights. Two selected lines of quail, 1 line selected for parthenogenesis and 1 line that was unselected for the parthenogenetic trait (control), were utilized in a 2 x 2 factorial arrangement of dam and sire lines to create 4 breeding treatments: control dams + control sires (CC), control dams + parthenogenetic sires (CP), parthenogenetic dams + control sires (PC), parthenogenetic dams + parthenogenetic sires (PP). Daily, fresh eggs were collected, labeled, weighed, and the germinal disc was classified as fertile, unfertilized without development, or parthenote. Yolk, albumen, and shell weights were obtained, and their weights were also calculated as percentage of total egg weight. A dam main effect revealed heavier weights for total egg, yolk, albumen, and shell as well as a larger percentage of albumen and ratio of albumen to yolk in parthenogenetic line dams versus control line dams. However, the percentage of yolk was higher for control than parthenogenetic line dams. The increase in total egg and egg component weights due to the parthenogenetic trait suggests that the transit time of the egg through the oviduct is altered. Perhaps transit through the magnum and uterus is delayed the most yielding greater albumen and shell weights, respectively. [ABSTRACT FROM AUTHOR]

A 1.5-year-old Polish hen was presented with a history of watery droppings and poor vent tone. Results of diagnostic tests revealed blood lead at levels considered to be toxic. Chelation therapy was started with calcium ethylenediaminetetraacetate. The hen was laying eggs before, during, and after chelation therapy. Eggs were tested for the presence of lead by combining yolk and albumen together. Before chelation therapy, the level of lead in the egg tested was 14 μg. Two days after the end of chelation therapy, results of a second blood lead test revealed a drop to nontoxic levels. No lead was detected in the combined yolks and albumen of eggs collected 7–11 days after the end of chelation therapy. Four weeks after the end of chelation therapy, no lead was identified in the shells of tested eggs. [ABSTRACT FROM AUTHOR]

The relationships between the maturation of salted duck egg yolk and the changes of physicochemical, texture and rheological properties were investigated by instrumental analyses. For the physicochemical properties, the apparent oil yield rate and oil extraction rate of salted duck egg yolk respectively increased during salting. The surface hydrophobicity also had an increasing trend and achieved a maximum value of 96.961S 0 , however, the particle size and zeta potential had significant decrement because of the protein accumulation. For texture, the parameters of hardness (858.91–2396.46 N), adhesiveness (2.64–5.11 Ns), springiness (0.28–0.43 mm), gumminess (352.34–918.29 N), and chewiness (139.39–417.45 N) had prominent increases during salting, while cohesiveness had a reverse trend. For the rheological characteristics, the gelatinization of yolk caused by salt resulted in the increments of elastic and viscous modulus. These significant alterations on yolk indicated that the micro-structure of yolk protein had changes that induced by NaCl in the process of curing. The equilibriums of three properties achieved during 20–25 days salting implied the maturation of salted duck egg yolk. Meanwhile, the composition and polypeptide chains of yolk did not degrade or aggregate during salting according to the gel electrophoresis. [ABSTRACT FROM AUTHOR]

An important and timely topic in the food industry, it is pasteurized liquid egg products, which have great utility in many industry and not only being sought ever more by consumers. The purpose of this paper is to verify nutritional properties and microbiological quality throughout the shelf life recommended by the manufacturer and to highlight their degradation. The physicochemical and microbiological quality assessment was performed on liquid pasteurized white and yolk, packed in a 2 kg bag-in-box in refrigerator (0 ... + 4 °C), and consisted in determining the pH value, nitrogen slightly hydrolyzable and microbiological analyzes were carried out according to the standards in force. The pH value increased during the shelf life from 8.29 (first day) to 8.98 (day 28), similar to pasteurized liquid yolk, the variation limits being between 5.93 and 6.04. Also, the slightly hydrolyzable nitrogen content was increased in the analyzed pasteurized liquid white (from 9.27 mg NH3/100 g on the first day to 14.73 mg NH3/100 g for the last day of storage), as well as in pasteurized liquid yolk to 6.57 mg NH3/100 g in the fresh product to 10.82 mg NH3/100 g in the stored product for 28 days). For the monitored microbiological indicators we also noticed an increase in their values during the storage period in the two types of analyzed egg products. The conclusion of the study is the highlight of existence a positive correlation between physical and microbiological indicators for both pasteurized liquid white and yolk analyzed. [ABSTRACT FROM AUTHOR]

The present work characterized the effects of pre-treatments on the protein profile and microstructure of granule fractions from egg yolk. The granule microstructure was studied using confocal laser scanning microscopy (CLSM). The protein profiles of the pre-treated granule and the corresponding plasma fraction were studied using 2D gel electrophoresis techniques. Further, we explored the potential for using high hydrostatic pressure (HHP) to promote disintegration of the granule structure. The CLSM micrographs provided evidence of the substantial disintegration of granules due to HHP (600 MPa/5 min). Results from high performance liquid chromatography (HPLC) analysis indicated high concentrations of folate in the plasma fractions (230 µg/g dry matter) separated from the HHP-treated granule. Sodium Dodecyl Sulphate–Polyacrylamide Gel Electrophoresis (SDS-PAGE) analysis revealed the localization of phosvitin in the plasma fraction, which correlated with higher folate concentrations. The results demonstrate that phosvitin and folate were stable under the HHP conditions applied in this study. These findings provide evidence of a putative interaction between phosvitin and folate, and offer an improved model for the structure of granule. [ABSTRACT FROM AUTHOR]

Lutein is an essential dietary carotenoid with health benefits and is inter alia responsible for the colouration of egg yolk. The relationship between lutein accumulation and egg yolk colouration was therefore studied in more detail. After feeding a low-luteine diet for 21 days, 14 birds (Lohmann brown hens aged 20 weeks) were fed a diet containing marigold (80 mg lutein/kg feed) and 14 other birds were fed a diet containing oleoresin (45 mg lutein/kg feed) for 21 days; for both groups of birds, this feeding period was followed by withdrawal for 21 days. The Roche YolkColour Fan (RYCF) score (0 to 15, where higher values denote greater colour intensity; R²=0.87; P<0.01) and redness (R²=0.89; P<0.01) increased with increasing lutein content of egg yolk. Total carotenoid content had a poor relationship with lightness (R2=0.13; P>0.05) and yellowness (R²=0.12; P>0.05) of the yolk. It may be concluded that increased lutein is potentially responsible for an increased RYCF score and redness (a*), but decreased yellowness (b*) and lightness (L*), of egg yolk. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effects of storage duration (0, 8, 16, 24, 32 d; 22 °C, 75% relative humidity) or freshness of hen eggs on the levels of protein-bound N ε -carboxymethyllysine (CML) in the albumen and yolk of raw eggs and their heat-treated (80 °C, 6 min; 100 °C, 30 min) counterparts. The mean CML level of raw albumen was significantly affected (p = 0.001) by the storage time of eggs, which was increased by 127% during the 32 d of storage. In addition, after 8, 16, 24 and 32 d storage of raw eggs, the average CML levels in their heat-treated albumen increased by 17%, 23%, 113%, and 157%, respectively, compared to that without storage (3.56 ± 2.32 mg/kg). This promoting effect of increased storage duration of raw eggs on the CML formation in albumen was somewhat tied to the continuous increase of pH and decrease of Haugh units. However, the storage time of eggs had no noticeable effect on the CML levels of either raw or heat-treated yolk, implying the great disparity in the major compounds and/or chemical reactions contributing to CML formation between the yolk and albumen of hen eggs. • Raw eggs stored longer had more Nε-carboxymethyllysine (CML) in the albumen. • Less fresh eggs led to more CML formed in the albumen during later heating. • Egg freshness didn't significantly affect the CML levels in raw and heated yolk. [ABSTRACT FROM AUTHOR]