Hen Egg Yolk Research Articles

Fabrication and characterization of emulsion stabilized by table egg-yolk granules at different pH levels.

The egg yolk is complex, which makes it difficult to understand why mayonnaise can be stabilized into a high internal-phase emulsion. This study aimed to assess the possibility of developing oil-in-water emulsions through unmodified natural egg-yolk granules (EYGs) at various pH levels, to further understand the precise mechanism of mayonnaise. Egg-yolk granules were obtained from hen egg yolk by centrifugation. The sizes of the EYGs were characterized using dynamic light scattering (DLS). Zeta potential of EYGs was detected by DLS and its microstructure was observed by microscope and scanning electron microscope (SEM). Oil / water emulsions were made with EYGs and the size distribution and creaming index of those emulsions were measured at different storage times (1 h and 14 days). The interfacial morphology of EYGs was observed using the emulsion polymerization method. Our results suggested that the prepared EYGs were mainly in an aggregated state but individual EYGs displayed spherical shapes, with a size of 1.0 ± 0.2μm. The emulsion stabilized by EYGs displayed better stability against creaming at acidic pH (<4.0). At the same time, the interfacial morphology and microscopic observation of the emulsions strongly demonstrated that the emulsions were of the Pickering type. The above results are of great importance for an understanding of the mechanism by which mayonnaise is stabilized by egg, together with the applications of egg in food formulations. © 2019 Society of Chemical Industry.

Chemical‐Free Approach for Z‐Isomerization of Lycopene in Tomato Powder: Hot Air and Superheated Steam Heating above the Melting Point of Lycopene

AbstractZ‐isomers of lycopene exhibit higher bioavailability and antioxidant capacity than those of the all‐E‐isomer. Therefore, it is important to develop an efficient and environmentally friendly procedure for Z‐isomerization. The current methods for Z‐isomerization of (all‐E)‐lycopene use toxic chemicals such as organic solvents and catalysts. This study is aimed to develop a chemical‐free method for Z‐isomerization of (all‐E)‐lycopene in tomato powder by hot air and superheated steam heating. The Z‐isomerization reaction is promoted by heating above the melting point of lycopene. When heated with superheated steam, the thermal decomposition of lycopene is suppressed compared to that when heated with hot air. When tomato powder is heated at 240 °C for 5 min by superheated steam, the total Z‐isomer content and remaining lycopene are 69.0% and 90.7%, respectively, while with hot air heating, the total Z‐isomer content and remaining lycopene are 69.9% and 68.0%, respectively. These results indicate that the thermal Z‐isomerization of lycopene occurs in the molten state and heating in a low oxygen atmosphere suppresses the thermal decomposition of lycopene.Practical Applications: Tomato powder rich in lycopene Z‐isomers is an important ingredient for the food and animal feed industries. Since Z‐isomers of lycopene are more soluble in solvents including ethanol which is a low‐toxicity and environmentally friendly solvent, the efficiency of lycopene extraction with ethanol can be improved by using the Z‐isomer‐rich tomato powder as a raw material. The obtained Z‐isomer‐rich extract has a high added value because the Z‐isomers have higher bioavailability and antioxidant capacity than those of the all‐E‐isomer. In addition, since lycopene Z‐isomers exhibit higher accumulation efficiency and better color improvement in hen egg yolks than those of the all‐E‐isomer, Z‐isomer‐rich tomato powder is an effective animal feed.

The Important of Beta Carotene on Poultry Nutrition

Beta carotene (BC), the primary source of vitamin A in poultry rations, is one of the most important carotenoids. Under the influence of enzymes, β-carotene is converted to vitamin A. The BC molecule is a double retinal structure and theoretically gives 2 molecules retinal. Its biological activity is only half of retinal. Conversion of carotenoids to retinol is rarely 100%. Thus the vitamins of various foods are expressed in terms of the potential retinol equivalence (RE). BC is absorbed from the duodenum and if there is oil in the intestinal tract, it is absorbed faster. Oxidatively converting BC into vitamin A is mainly carried out in the intestinal brush border membrane, organs such as the liver, kidney and lungs. BC egg yolk is transported to and stored in immune organs and similar tissues. The BC content of the egg of the poultry varies. BC contents of hen eggs are low, while BC contents of eggs of wild birds are between 25-30%. Despite depletion of BC in the liver it's transfer to the egg continues. Since poultry can not synthesize β-carotene, it must be taken from outside. Products such as yellow corn, marigold and alfalfa are very rich sources of β-carotene. BC is abundant in egg yolks, milk, butter and liver. BC is effective in the pigmentation of skin and egg yolks of hens. Due to BC's antioxidant properties prevents deterioration of egg and meat. It has also been shown that BC has important effects on the immunity and endocrine system. BC, strengthens see function, reduces the risk of cardiovascular disease, prevents inflammation and some types of cancer. Studies have shown that BC enhances the immune system by raising antibody response in poultries and prevents acute respiratory tract infections. In this review article, the introduction of BC, its functions, effects on poultry nutrition were investigated.

Choline supplementation alters egg production performance and hepatic oxidative status of laying hens fed high-docosahexaenoic acid microalgae

The purpose of the current study was to investigate the effect of choline as a means of increasing docosahexaenoic acid (22:6 n-3, DHA) deposition in egg yolks of hens fed a high-DHA microalgae product. Fifty-six, 26-wk-old, White Leghorn hens were kept in individual cages and randomly allocated to 1 of 4 dietary treatments, each with 7 replicate groups of 2 hens (n = 7 per treatment). The experimental diets were corn and soybean meal based, with 0% microalgae (control), 1% microalgae and no additional choline chloride (Alg), and Alg plus choline chloride at 0.1% (Ch0.1) and 0.2% (Ch0.2). The feeding trial lasted 16 wk. The data were fit as a general linear mixed model to generate least square means in response to diet. Variables measured multiple times during the study were fit as repeated measures. Using orthogonal contrasts, Alg was compared to control, and Ch0.1 and Ch0.2 were compared separately to Alg. Ch0.1 increased hen day egg production (P < 0.05) and Haugh unit (P < 0.05), and reduced feed conversion ratio (P < 0.05) compared to Alg, but Ch0.2 did not. Alg increased egg DHA (P < 0.001), phosphatidylethanolamine (P < 0.05), and phosphatidylcholine (P < 0.001) compared to control, but Ch0.1 or Ch0.2 had no effect compared to Alg (P > 0.05). In the liver, Alg increased lipid peroxidation products compared to control (P < 0.01), and Ch0.1 reduced them compared to Alg (P < 0.01). Both Ch0.1 and Ch0.2 increased hepatic concentrations of γ- (P < 0.05; P < 0.001) and α-tocopherol (P < 0.01; P < 0.001), and Ch0.1 increased γ-tocopherol concentration in eggs compared to Alg (P < 0.05). The results from the current study suggest that supplemental choline chloride in hen diets containing microalgae can improve production performance and egg quality, and protect the liver from oxidative stress.

Reduction in Oviposition of Poultry Red Mite (Dermanyssus gallinae) in Hens Vaccinated with Recombinant Akirin.

The poultry red mite (PRM), Dermanyssus gallinae, is a hematophagous ectoparasite of birds with worldwide distribution that causes economic losses in the egg-production sector of the poultry industry. Traditional control methods, mainly based on acaricides, have been only partially successful, and new vaccine-based interventions are required for the control of PRM. Vaccination with insect Akirin (AKR) and its homolog in ticks, Subolesin (SUB), have shown protective efficacy for the control of ectoparasite infestations and pathogen infection/transmission. The aim of this study was the identification of the akr gene from D. gallinae (Deg-akr), the production of the recombinant Deg-AKR protein, and evaluation of its efficacy as a vaccine candidate for the control of PRM. The anti-Deg-AKR serum IgY antibodies in hen sera and egg yolk were higher in vaccinated than control animals throughout the experiment. The results demonstrated the efficacy of the vaccination with Deg-AKR for the control of PRM by reducing mite oviposition by 42% following feeding on vaccinated hens. A negative correlation between the levels of serum anti-Deg-AKR IgY and mite oviposition was obtained. These results support Deg-AKR as a candidate protective antigen for the control of PRM population growth.

Resistance and tolerance to mixed nematode infections in relation to performance level in laying hens

Modern chickens have been genetically developed to perform high under optimal conditions. We hypothesized that high-performance is associated with a higher sensitivity to environmental challenges in laying hens. By using nematode infections as an environmental stressor, we assessed performance-level associated host responses in a high (i.e. Lohmann Brown Plus, LB) and in a lower performing, a so-called dual-purpose chicken genotype (i.e. Lohmann Dual, LD). The hens were infected with 1000 eggs of Ascaridia galli and Heterakis gallinarum at 24 weeks of age. Hen performance parameters, humoral immune responses in plasma and egg yolks and worm burdens were assessed at several occasions over a period of 18 weeks post infection (wpi).While infections had no significant effect on feed intake (P = 0.130) and body weight in both genotypes (P = 0.392), feed conversion efficiency was negatively affected by infections (P = 0.017). Infections reduced both laying rate and egg weight and thereby per capita egg mass in both genotypes (P < 0.05). While laying rate in infected LB hens decreased significantly (P < 0.05) in the early infection period (i.e. by 3 wpi), the decrease in LD hens appeared much later (i.e. by 14 wpi). Worm burdens resulting from the experimental infection were not different between the genotypes for both worm species (P > 0.05), whereas LB hens were more susceptible (P < 0.05) to re-infections than LD hens. Changes in humoral immune responses (i.e. ascarid-specific IgY antibodies in plasma and egg yolks) of the two genotypes over time reflected closely the corresponding changes in larval counts of the hens, descending from both experimental and subsequent natural infections in both genotypes. Infections caused a shift in egg size classes, leading to smaller frequency of larger eggs in both genotypes. Infections reduced egg weight (P = 0.018) and led to a reduced fat content in the egg yolks (P = 0.045). The proportion of poly-unsaturated fatty acids (PUFA), especially n-6-PUFA, was also lower in egg yolks of the infected hens (P = 0.032).We conclude that tolerance to nematode infections in laying hens is dependent on host-performance level. The impairment in host tolerance was both genotype and time dependent, likely due to differences in genetic programming for production peak and persistency of the two genotypes. The two genotypes exhibited similar levels of resistance after a fully controlled experimental infection, but the high performing hens were more susceptible to subsequent natural infections. Infections negatively affected economically important egg-quality traits, including egg weight, fat content and fatty acid profiles in egg yolks.

Comparative proteomic analysis of hen egg yolk plasma proteins during embryonic development.

Avian egg yolk provides essential nutrients and physiological support for the developing embryo. To reveal the dynamics of yolk proteins during the entire period of incubation, we analyzed the alterations of egg yolk plasma proteins at different times during incubation (day 0, 7, 14, and 18). Day14 (D14) of incubation was considered as the key point on the alteration of egg yolk proteins according to the SDS-PAGE analysis. The two-dimensional electrophoresis-based comparative proteomic analysis was conducted, and 26 spots representing 13 proteins were detected with significant changes in abundance. An accelerating transfer of ovalbumin from egg white into egg yolk was observed at D14 in fertilized eggs but not detected in unfertilized eggs, indicating an unrevealed absorbing pathway for the egg proteins/peptides particularly in fertilized eggs. Meanwhile, the abundance of yolk riboflavin-binding protein constantly decreased after D14, which might meet the need for essential riboflavin during embryo development. PRACTICAL APPLICATIONS: These findings provide fundamental insight into the effects of incubation on egg yolk plasma protein alterations during the entire embryonic development for a better understanding of plasma protein biological functions, especially in nutrient transportations and the formation of embryonic organs.

Characterization and production of IgY antibodies anti-Photobacterium damselae subsp. piscicida: Therapeutic and prophylactic use in Rachycentron canadum

Pseudotuberculosis is caused by Photobacterium damselae subsp. piscicida (Phdp), an important pathogen in marine fish culture. In this study, Phdp isolated from a Rachycentron canadum farm was used to produce anti-Photobacterium damselae IgY and its protective effect were evaluated in R. canadum challenged with the homologous strain. The IgY was obtained from egg yolks of White Leghorn hens using polyethylene glycol precipitation method. Anti-Phdp IgY showed strongly specific reaction against Phdp proteins. Finally, it was performed the antibody efficacy in vivo to determinate their prophylactic and therapeutic effects during sepsis in R. canadum. For this, fish received anti-Phdp IgY 48 h and 15 days before the challenged with the homologous bacteria of Phdp. In these groups, it was observed less liver and kidney lesions comparing to control group, which was also correlated to the biochemical profile. In this study, it was also developed an immunohistochemistry test that presented highly specificity and affinity to Phdp that could be used as screening method for the diagnosis and analysis of pathogenesis of this disease. It was concluded that the IgY produced effectively inhibited the dissemination of this bacteria that could be helpful for the treatment and prophylaxis of this disease.

Egg yolk phospholipids: a functional food material to generate deep-fat frying odorants.

Phospholipids are an important precursor for the generation of carbonyl compounds that play a significant role in the characteristic aroma of deep-fat fried foods. Phospholipids extracted from hen egg yolks were added into sunflower oil (2.0g kg-1 ) and heated with or without chicken meat at 160 °C for 10min, and then dynamic headspace extraction and gas chromatography-mass spectrometry were used to extract and analyse the volatiles. The results showed that the characteristic deep-fat frying odorants, such as (E,E)-2,4-decadienal and (E,Z)-2,4-decadienal, as well as 1-octen-3-one, (E)-2-nonenal, octanal, methional, dimethyl disulfide and alkylpyrazines, had increased by 3-65 times in the sunflower oil with added phospholipids, and increased up to six times in chicken meat that had been treated with phospholipids prior to heating. There is potential for the food industry to use low levels of phospholipids, particularly egg yolk phospholipids, to increase deep-fat frying odorants in a wide range of deep-fried products. © 2019 Society of Chemical Industry.

Egg Yolk Antioxidants Profiles: Effect of Diet Supplementation with Linseeds and Tomato-Red Pepper Mixture before and after Storage.

This study evaluated the effect of dietary incorporation of linseed alone or along with dried tomato paste-pepper powder mix on egg physical characteristics, antioxidant profiles, lipid oxidative status, and yolk coloration before and after storage at 4 °C for one month. Sixty Novogen White laying hens, 27 weeks-old, were divided into three groups and given 100 g/hen/day of a standard diet (C), standard diet containing 4.5% of ground linseed (L), linseed diet containing 1% of dried tomato paste and 1% of sweet red pepper (LTP). Linseeds increased (p < 0.05) egg yolk antioxidant capacity but not lipid oxidative stability (p > 0.05). However, dietary inclusion of LTP did not improve fresh egg yolk antioxidant activity and lipid oxidation stability (p > 0.05). With reference to the stored eggs, only antioxidant activity measured by phosphomolybdenum reduction and lipid oxidative stability were influenced (p < 0.05) by the dietary treatment. Fresh egg yolk of hens fed on linseeds tended to have a slightly more yellow, redder, and less light color than the eggs of hens fed with the control diet. Dietary supplementation of LTP increased (p < 0.05) the Roche yolk color fan (RYCF) score and redness (a*) and decreased (p < 0.05) lightness (L*) without affecting (p > 0.05) saturation (C*). Storage of hens’ eggs fed on the control diet did not influence (p > 0.05) yolk color.

Complex investigation of the five 19th century Russian-Lipovan icons

For a better description and chronology of the liturgical art of the Russian-Lipovan community of Romania and, in view of correct attestation, a set of five icons presumed painted in the first half of the 19th century belonging to the patrimony of Antim Monastery (Bucharest) and One-wood Monastery (Valcea county), have been investigated by means of non-invasive Digital Radiography (DR), X-Ray Fluorescence (XRF), Fourier Transform Infrared (FT-IR) and Raman (FT-Raman) Spectroscopy. Only a few fragments being left after some restorations have been analysed by invasive Epithermal Neutron Activation Analysis (ENAA).DR proved a relative good state of conservation of wooden panel evidencing the presence of different metallic artefacts, XRF confirmed the presence of Ca, Cr, Fe, Ba, Ag, Hg, Au and Pb as components of pigments or metallic ornaments, ENAA, although being reduced to only a few fragments, allowed to evidence the presence of Sr, as well as of small amounts of Zn and As, most probably as impurities. Judging on FT-IR data, a protein-rich binder, most probably hen egg yolk was used, suggesting tempera as the main painting technique. Complementarily, FT-Rama spectroscopy showed that in all cases painters had used vermilion, red lead and at a less extent - litharge as red pigments, while white lead, anhydrite, chalk had been used as white pigments or as components of the primer. Only in the case of the most elaborated Saint Nicholas icon, FT-Raman spectroscopy allowed to identify the use of chrome yellow and ultramarine. All data suggest the first half of the 19th century as a possible age of the icon painted in local ateliers belonging to the Russian-Lipovan community of Romania.

Highly specific and sensitive anti-Strongyloides venezuelensis IgY antibodies applied to the human strongyloidiasis immunodiagnosis

Due to the epidemiological problem of the neglected condition of human strongyloidiasis, rapid and effective diagnosis is extremely important, with the development of new diagnostic tools being essential to reduce infections and chronic cases. Avian immunoglobulin Y (IgY) technology is an alternative for antibody production that has high specificity and profitability. This study aimed to produce and fractionate IgY antibodies from the egg yolks of hens that were immunized with the total antigenic extracts of Strongyloides venezuelensis infectious filariform larvae (iL3) and parthenogenetic females (pF). IgY antibodies were then evaluated by their recognition of antigenic proteins, evolutive helminth forms, and serological diagnosis of human strongyloidiasis by the detection of immune complexes in serum samples. Egg yolks were fractionated to obtain IgY antibodies by thiophilic interaction chromatography. Immune complex detection in serum samples showed diagnostic values for anti-iL3 IgY and anti-pF IgY antibodies at 95.56% and 88.89% sensitivity and 95.56% and 91.11% specificity, respectively. Therefore, IgY technology is a promising tool for the detection of blood circulating Strongyloides antigens, with possible application as a serological diagnostic method.

Profiling and Qualitative Assessment of Enzymatically and Thermally Oxidized Egg Yolk Phospholipids using a Two‐Step High‐Performance Liquid Chromatography Protocol

AbstractA two‐step high‐performance liquid chromatography (HPLC) method for the profiling and qualitative assessment of oxidized phospholipids (oxPL) present in foods was developed. The applicability of the investigated two‐step HPLC protocol was verified for separation of enzymatically and thermally oxidized hen egg yolk phospholipids (PL) as a relevant food model. In the first step, seven individual PL classes were separated using hydrophilic interaction liquid chromatography (HILIC). The collected fractions of two main egg yolk PL classes—phosphatidylethanolamines and phosphatidylcholines—were further directed to the second step of separation aimed at profiling and qualitative assessment of their oxidized species. For this purpose, the reverse phase (RP) chromatography coupled to charged aerosol, ultraviolet detection (UV) and mass spectrometry detection were employed. A database of potential oxPL including primary (hydroperoxides) and long‐chain secondary PL oxidation products (epoxides, alcohols, and ketones) as well as some of their possible combinations was created. Additionally, the results were compared with the profiles of PL hydroperoxides obtained using thin layer chromatography (TLC) with N,N‐dimethyl‐p‐phenylenediamine visualization.

Synergistic effect of anti-Helicobacter pylori urease immunoglobulin Y from egg yolk of immunized hens and Lactobacillus johnsonii No.1088 to inhibit the growth of Helicobacter pylori in vitro and in vivo

Helicobacter pylori is a pathogenic bacterium that infects the stomach, causing chronic gastritis; and it is also considered to be related to the occurrence of gastric cancers. Although some eradication regimens including multiple antibiotics have been developed, the emergence of resistance to antibiotics becomes problematic. Therefore, other approaches to compensate or augment the effects of standard regimens are needed. In this study, we examined the possible synergistic effects of anti-H. pylori urease IgY and Lactobacillus johnsonii No.1088 (LJ88) both in vitro and in vivo. Anti-H. pylori urease IgY was purified from egg yolks laid by the hens immunized with urease purified from H. pylori. LJ88 is a unique strain of lactic acid bacterium isolated from human gastric juice, and it has been reported to inhibit H. pylori both in vitro and in vivo. The in vitro mixed culture study showed that anti-H. pylori urease IgY augmented the anti-H. pylori activity of LJ88 against both clarithromycin-sensitive and -resistant H. pylori strains. In a germ-free mice infection model, combined administration of daily anti-H. pylori urease IgY and weekly living LJ88 significantly reduced H. pylori infections, whereas either monotherapy did not. In an in vivo human gut microbiota-associated mice model, not only daily administration of living LJ88 but also heat-killed one significantly reduced an H. pylori infection in the stomach when combined with anti-H. pylori urease IgY. The extent of reduction of the stomach H. pylori by such a combination therapy was larger than that reported for LJ88 monotherapy. These results taken together revealed a synergistic effect of anti-H. pylori urease IgY and living or heat-killed LJ88, thus suggesting that such a combination might be a promising therapy to possibly compensate and/or augment standard anti-H. pylori regimens.

Effect of Chili Leaf Powder on Laying Hen Performance, Egg Quality and Egg Yolk Cholesterol Levels

Effect of Chili Leaf Powder on Laying Hen Performance, Egg Quality and Egg Yolk Cholesterol Levels

Modulating effect of a new ester, 28-O-phosphatidylbetulin (DAPB), obtained from hen egg yolk lecithin and betulin on lymphocyte subsets and humoral immune response in mice

Context: Leaf extracts of plants of the genus Betula have traditionally been used as diuretic, anti-rheumatic and diaphoretic preparations. One of the main active ingredients of Betula bark is betulin, lupane-type triterpene alcohol, with multiple biological activities.Objectives: The aim of this study was to investigate in vitro and in vivo immunomodulatory effects of a newly synthesized ester of betulin: 28-O-phosphatidylbetulin [28-O-(1,2-diacyl-sn-glycero-3-phospho)-betulin, DAPB] in comparison with betulin in mice.Materials and methods: Cytotoxic activity of DAPB or betulin was tested against non-cancer (D10.G4.1 and J774E.1) and cancer (GL-1; CL-1 and Jurkat) cell lines. The in vivo part assessed total lymphocyte count, weight ratio and subsets of lymphocytes in the lymphatic organs, and humoral immune response to sheep erythrocytes (SRBC).Results: In vitro assay showed that DAPB, contrary to betulin, had no antiproliferative activity. Exposure to four doses of DAPB increased the absolute count of immature CD4+CD8+ thymic cells as well as the percentage and absolute count of mature CD4+ and CD8+ thymocytes. DAPB enhanced the percentage or absolute count of CD3+ cells in spleen and lymph nodes with corresponding decrease in the percentage and/or absolute count of CD19+ cells. Both DAPB and betulin enhanced the percentage and absolute count of CD8+ lymphocytes in lymph nodes. In SRBC-immunized mice, betulin contrary to DAPB enhanced the number of splenocytes producing anti-SRBC antibodies (PFC). Both DAPB and betulin increased the level of total (IgM + IgG) and IgG titers.Conclusion: Despite the lack of cytotoxic activity, DAPB shows valuable immunomodulatory properties.

Effect of dietary fat on the content of vitamins and carotenoids in egg yolks

Abstract This study evaluated the effects of fat source in the diet on the content of vitamins E and A, and carotenoids in egg yolks. Hisex Brown hens aged 49–56 weeks were fed on diets that differed in the content of crude fat (a diet without fat and diets supplemented with rapeseed or palm oil at 40Â g/kg). Diets of all hens contained 3% dehydrated alfalfa (a source of carotenoids). Measurement of vitamin and carotenoid content in yolks was carried out by HPLC methods. Supplements of fat increased the α-tocopherol content in egg yolks by 80.1% (rapeseed oil) and 72.1% (palm oil), respectively. The increase of lutein, zeaxanthin and retinol in yolks of hens fed dehydrated alfalfa and oils was less pronounced (varied from 13.4% to 26.5%). Effects of dietary fat supplementation on deposition of lipophilic vitamins and carotenoids were small or statistically non-significant. The saturation of diets with fat increased the hen-day egg production and decreased the feed intake. It can be concluded that dietary inclusion of fat increased the deposition of α-tocopherol, retinol and carotenoids in eggs of hens fed a diet containing dehydrated alfalfa.

Specific Chicken Egg Yolk Antibody Improves the Protective Response against Gallibacterium anatis Infection.

Gallibacterium anatis is a pathogen associated with peritonitis and salpingitis in chickens and other avian species. Novel safety prevention strategies are urgently needed because of widespread multidrug resistance and antigenic diversity. The objective of this study was to produce a specific chicken egg yolk antibody and evaluate its protective response against a G. anatis infection model in 4-week-old chicks. Enzyme-linked immunosorbent assays showed that hens immunized with the recombinant N terminus of Gallibacterium toxin A (GtxA-N) had significantly increased antibody titers against GtxA-N in serum and egg yolk IgY. Western blotting showed that IgY antibody had specificity against GtxA-N in the egg yolks of immunized hens. The growth of G. anatis in brain heart infusion (BHI) broth and agar was significantly inhibited by the GtxA-N-specific IgY antibody. The protective effects of the specific IgY antibody were evaluated in G. anatis-infected chicks after intramuscular injection (10 mg/ml). The anti-GtxA-N antibody titers in the sera of G. anatis-challenged chicks following an injection of specific IgY antibody were significantly higher than those of the control and the nonspecific IgY groups, but lower lesion scores for the peritoneum, liver, and duodenum were found after specific IgY antibody treatment. The results from this study suggest that the GtxA-N-specific IgY antibody could potentially improve the protective response against G. anatis infection in chicks.

Low Density Lipoprotein - important player in increasing cryoprotective efficiency of soybean lecithin-based bull semen extenders.

Currently, considering cryopreservation of bull semen, there is no clear consensus over the comparability of cryoprotective efficacy of extenders with soybean lecithin and those based on egg yolk. The objective of this study was to prove the use of Low Density Lipoprotein (LDL) extracted from hen-egg yolk as an enhancing factor for soybean lecithin-based extenders. In total, 35 ejaculates of (seven bulls x five ejaculates per bull) were collected and cryopreserved at a commercial insemination centre. The effect of the LDL addition to the extenders AndroMed® and Bioxcell® was tested in a 6% (v/v) concentration on spermatozoa after thawing. Modified extender composition effects were assessed on sperm functional parameters motility, plasma membrane, mitochondrial membrane potential and acrosomal integrity after thawing by CASA, flow cytometry and fluorescent microscopy, respectively. Based on kinematic parameters determined from CASA, k-means cluster analysis was used to classify individual spermatozoon into specific subpopulations (fast, medium fast and slow). A subpopulation of fast spermatozoa was increased in the presence of LDL in both selected extenders (P < 0.05). Moreover, the positive effect of LDL on sperm motility was confirmed by decreasing the percentage of sperm in slow subpopulation (P < 0.05). The effect of LDL addition on the incidence of spermatozoa with intact plasma membrane was not demonstrated in any case of extender used (P > 0.05). The percentage of sperm with intact acrosome was improved when LDL was added to Bioxcell® extender (P < 0.05). On the other hand, addition of LDL to AndroMed® extender improved mitochondrial intactness after thawing (P < 0.05). In conclusion, our results showed that adding LDL to selected soybean lecithin-based extenders considerably ameliorated the functional parameters of spermatozoa after thawing and thus this lipoprotein could represent an improving agent for soybean lecithin-based extender for bull semen cryopreservation.

Effect of dietary supplementation with hyperimmunized hen egg yolk powder on diarrhoea incidence and intestinal health of weaned pigs

ABSTRACTThis study investigated the effects of dietary supplementation with hyperimmunized egg yolk powder (HEYP) on diarrhoea incidence and intestinal health of weaned pigs. Two kinds of HEYP were used, one is multivalent HEYP against mixed Escherichia coli (E. coli) (K88-K99-987P) antigens and the other is the mixture of three monovalent HEYP against single E. coli K88, K99 or 987P antigen, respectively. A total of 180 weaned pigs were assigned to 5 dietary treatments: control diet (CON), 3 or 30 g/kg of two kinds of HEYP diets. Pigs fed HEYP diets had a lower diarrhoea incidence, lower E. coli numbers in faeces and ameliorated mucosal morphology in the duodenum, accompanied by a tendency to reduce inflammation response and intestinal permeability compared with CON. There were no significant differences in the dosage effects of either HEYP. Therefore, anti-(K88-K99-987P) HEYP might be an effective feed additive to protect weaned pigs against enterotoxigenic E. coli⁠.