Yolk Content Research Articles

Does dietary linseed or canola oil affect lipid metabolism, immunity, and n-3 polyunsaturated fatty acids content in quail eggs?

One of the most intriguing areas of research and innovation in the animal production and food sector recently has been designed-enriched products. These items are regarded as functional foods because they feature components that have advantageous physiological impacts on human health. In the production of poultry, designed eggs constitute a significant category of functional foods. The present study hypothesized that adding different kinds of oils to quail diets will help produce designer eggs rich in omega-3 and 6 fatty acids in addition to enhancing productive performance. So, this study examined how linseed (flaxseed) and canola oils with various levels can affect lipid metabolism, immune function, and the amount of n-3 polyunsaturated fatty acids (n-3 PUFA) in Japanese quail eggs. This work was conducted using 3 different vegetable oils (sunflower, linseed, and canola oils) and 3 different antioxidant supplements (0, 250 mg vitamin E/kg feed, and 1,000 mg ginger/kg feed) in a 3×3 factorial experiment. When linseed or canola oil was added to the diet, the number of fatty acids in the egg yolks of Japanese quail layers fell by (12.7 and 18.9%) and (41.4 and 24.6%), respectively. The amounts of saturated and monounsaturated fatty acids in total eggs fell by 21.9 and 14.6% and 24.5 and 15.8%, respectively, at 20 wk of age. However, when linseed and canola oil were added to the diet, the sum n-3 PUFA content in the egg yolk of Japanese quail-laying hens was noticeably raised at 15 and 20 wk of age. At 15 and 20 wk of age, the same groups' total n-6 PUFA content considerably increased compared to the group that did not receive flaxseed. In conclusion, during the laying period of Japanese quail, linseed oil, canola oil, vitamin E, or ginger positively affected productivity, blood hematology, constituents, resistance, lipid digestion system, and antioxidative properties in serum and egg yolk.

Variation in element contents among free-range turkey egg yolks and albumens analyzed by inductively coupled plasma optical emission spectrometry

Poultry eggs are not only a source of nutrients for embryonic development, but also one of the main sources of food for humans. The demand for turkey eggs is increasing day by day due to their functional properties such as supporting muscle and cell formation and being beneficial to the immune and digestive systems. In addition, it contains essential elements such as iron at a reasonable level, which is among the reasons for the consumer's preference. The data on the element content of free-range turkey eggs, which is such an ancient food, is very scarce. This study focused on determining various element content of freerange turkey egg yolk and albumen by inductively coupled plasma optical emission spectrometry (ICP-OES). Within the scope of the research, sodium (Na), potassium (K), calcium (Ca), phosphorus (P), iron (Fe), manganese (Mn), magnesium (Mg), copper (Cu), zinc (Zn), chromium (Cr), boron (B), aluminum (Al), and lead (Pb) levels were determined in turkey egg yolk (n=52) and albumen (n=52) samples. Phosphorus was the most concentrated element in both egg yolk and albumen. Element contents in yolks were higher than those in albumen, except Na, K, B, Al, and Pb. The element with the lowest concentration was Al in turkey egg yolks, while Mg was the lowest analyzed element in albumens. This study separately exhibited the element content of turkey egg consumers in their preference for egg yolk or albumen

Dietary Morus alba L. leaf supplementation improves hepatic lipid accumulation of laying hens via downregulating CircACACA

Fatty liver hemorrhagic syndrome (FLHS) is the most common metabolic disease in laying hens. Morus alba L. (mulberry) leaf has the effect of regulating lipid metabolism. We evaluated the effects of dietary 3% mulberry leaf (MUL) supplementation in production performance, egg quality, and liver lipid deposition in laying hens. Differentially expressed genes and circRNAs in the liver were identified using whole-transcriptome sequencing. We also evaluated the effects of the MUL extract using an in vitro model of primary hepatocytes induced by free fatty acids and explored the role of key circRNAs in this process. Dietary supplementation with 3% MUL alleviated liver steatosis in laying hens, as shown by decreased fatty liver color score, relative liver weight (P < 0.01), and triglyceride levels (P < 0.05), and showed a tendency to reduce the mortality rate of laying hens (P=0.09). In addition, mulberry leaf supplementation significantly reduced cholesterol content in egg yolk (P < 0.01). Dietary mulberry leaf supplementation downregulated the expression of genes involved in fatty acid and cholesterol biosynthesis, and upregulated the expression of fatty acid oxidation-related genes in the liver. CircACACA, which is derived from exons 2 and 3 of the acetyl-CoA carboxylase alpha (ACACA) pre-mRNA, was significantly reduced in the MUL group (P < 0.01). Upregulation of circACACA expression reversed the lipid-lowering effect of mulberry leaf extract by upregulating sterol regulatory element-binding proteins 1 c (SREBP-1c) and fatty acid synthase (FASN) (P < 0.05). Overall, mulberry leaf is an effective therapeutic strategy for FLHS in hens and can improve liver lipid metabolism by downregulating circACACA.

The Effect of Egg Yolk on the Physical and Organoleptic Properties of Mayonnaise from Virgin Coconut Oil and Coconut Water

Mayonnaise is a semi-solid food ingredient produced by mixing vegetable oil with an emulsifier consisting of vinegar and egg yolks, and sugar or salt can also be added to taste. The purpose of this study was to evaluate the effect of egg yolk on the physical and organoleptic properties of mayonnaise made of virgin coconut oil (VCO) and coconut water. Mayonnaise is typically produced by mixing egg yolk (0, 5, 7, 9, 11) %, salt, sugar, xanthan gum, mustard, lime, coconut water and VCO (coconut water : VCO ratio = 4:1). Furthermore, homogenization was carried out using ultra turrax for 4 minutes at 15000 rpm until mayonnaise was formed. Analysis was carried out on viscosity, stability, organoleptic tests (color, taste, aroma, and texture) and chemical tests (moisture/water content, fat content, and protein content) as well as total plate number. The results showed that mayonnaise made of virgin coconut oil had stable properties. The highest viscosity value was 1040 cP in the concentration of 7% egg yolk. An increase in egg yolk content decreases the viscosity of mayonnaise. In organoleptic testing, it was found that the combination of coconut water and 7% egg yolk had a neutral preference for taste. For the color aspect, the results found were included in the like category, while for the aroma aspect, the results was included in the neutral category. The result found was classified as like for texture aspect. When compared to SNI 01-4473-1998, mayonnaise with a combination of coconut water and 7% egg yolk had a water content of 76.75% higher than SNI (max 30%), fat content 12.49% lower than SNI (min 65%), protein content 2.21% meets SNI requirements (min 0.9%), and total plate count (TPC) 2.7x102 colonies/gr meets SNI standards (max 1x104 colonies/g). Therefore, the mayonnaise produced in this study is classified as low fat.

Maternal provisioning interacts with incubation temperature to affect hatchling mercury exposure in an oviparous reptile.

The thermal environment experienced by developing embryos can influence the utilization of maternally provisioned resources. Despite being particularly consequential for oviparous ectotherms, these dynamics are largely unexplored within ecotoxicological frameworks. Here, we test if incubation temperature interacts with maternally transferred mercury to affect subsequent body burdens and tissue distributions of mercury in hatchling American alligators (Alligator mississippiensis). Nine clutches of alligator eggs were collected from a mercury-contaminated reservoir and incubated at either female- or male-promoting temperatures. Total mercury (THg) concentration was measured in egg yolk collected during incubation and in a suite of tissues collected from hatchlings. THg concentrations in residual yolk and blood were higher in hatchlings incubated at cooler, female-promoting temperatures compared to the warmer, male-promoting temperatures. THg concentrations in most tissues were positively correlated with THg concentrations in blood and dermis, and egg yolk THg concentration was the best predictor of THg concentration in many resultant tissues. Our results highlight a hereto unknown role of the developmental environment in mediating tissue specific uptake of contaminants in an oviparous reptile.

Unraveling the Potential of Orange Pulp for Improving Laying Rate, Egg Quality, Oxidative Stability, Fatty Acids Composition, and Reproductive Tract Morphology of Laying Hens.

The current study aimed to demonstrate the effects of dietary dried orange pulp (DOP) on the laying performance, egg quality, antioxidant status, yolk fatty acid composition, serum biochemistry, and reproductive tract morphology of laying hens. A total of 200 Lohman Brown Lite laying hens were randomly allotted into 4 dietary treatments with 10 replicates each. The experimental treatment groups were the control group, a basal diet containing 50 g DOP/kg feed (DOP5%), a basal diet containing 70 g DOP/kg feed (DOP7%), and a basal diet containing 100 g DOP/kg feed (DOP10%). Data were statistically analyzed by one-way ANOVA following a completely randomized design, and the incremental levels of dietary DOP were tested by orthogonal polynomial contrasts. The body weight gain, feed intake, egg production%, egg weight, egg mass, and feed conversion ratio of laying hens fed the DOP7% and DOP10% diets were greater (p < 0.01) than those fed the control diet. Eggs obtained from the DOP7% and DOP10% groups had a heavier shell weight% and shell thickness, as well as a greater yolk color score (p < 0.01; linear, p < 0.01). Dietary DOP improved the egg yolk concentrations of PUFA, n-3 PUFA, and n-6 PUFA (linear, p < 0.001; quadratic, p < 0.05), whereas the content of SFA was reduced (p < 0.001; linear, p < 0.001). The egg yolk cholesterol and triglyceride levels were linearly decreased (p < 0.001) with the inclusion of DOP in the diets of hens. After storage for 40 days, the malondialdehyde (MDA) contents in the egg yolk were reduced, whereas the glutathione peroxidase content was increased (p < 0.01) due to dietary DOP. The DOP7% and DOP10% hens had an obvious reduction in the levels of serum total lipids, total cholesterol, triglycerides, low-density lipoprotein, and MDA, whereas high-density lipoprotein and GPx levels were increased (p < 0.01) compared with those fed the control diet. The relative weights of the ovary, oviduct, uterus, and follicle of hens receiving diets containing 7% and 10% DOP were heavier (p < 0.01) than those of the control hens. Moreover, the number of large yellow follicles was increased (p < 0.001; linear, p < 0.001) in the hens-fed diets containing 7% and 10% DOP. In conclusion, dietary DOP at up to 100 g/kg of feed improves laying performance, health status, antioxidant capacity, egg nutritive value, and egg shelf life in laying hens.

Population divergence in maternal investment and embryo energy use and allocation suggests adaptive responses to cool climates.

The thermal sensitivity of early life stages can play a fundamental role in constraining species distributions. For egg-laying ectotherms, cool temperatures often extend development time and exacerbate developmental energy cost. Despite these costs, egg laying is still observed at high latitudes and altitudes. How embryos overcome the developmental constraints posed by cool climates is crucial knowledge for explaining the persistence of oviparous species in such environments and for understanding thermal adaptation more broadly. Here, we studied maternal investment and embryo energy use and allocation in wall lizards spanning altitudinal regions, as potential mechanisms that enable successful development to hatching in cool climates. Specifically, we compared population-level differences in (1) investment from mothers (egg mass, embryo retention and thyroid yolk hormone concentration), (2) embryo energy expenditure during development, and (3) embryo energy allocation from yolk towards tissue. We found evidence that energy expenditure was greater under cool compared with warm incubation temperatures. Females from relatively cool regions did not compensate for this energetic cost of development by producing larger eggs or increasing thyroid hormone concentration in yolk. Instead, embryos from the high-altitude region used less energy to complete development, that is, they developed faster without a concomitant increase in metabolic rate, compared with those from the low-altitude region. Embryos from high altitudes also allocated relatively more energy towards tissue production, hatching with lower residual yolk: tissue ratios than low-altitude region embryos. These results are consistent with local adaptation to cool climate and suggest that this is underpinned by mechanisms that regulate embryonic utilisation of yolk reserves and its allocation towards tissue, rather than shifts in maternal investment of yolk content or composition.

Effects of high incubation temperature on tight junction proteins in the yolk sac and small intestine of embryonic broilers

During the transition from incubation to hatch, the chicks shift from obtaining nutrients from the yolk sac to the intestine. The yolk sac tissue (YST) and small intestine serve as biological barriers between the yolk or gut contents and the blood circulation. These barriers must maintain structural integrity for optimal nutrient uptake as well as protection from pathogens. The objective of this study was to investigate the effect of high incubation temperature on mRNA abundance of the tight junction (TJ) proteins zona occludens 1 (ZO1), occludin (OCLN), claudin 1 (CLDN1), and junctional adhesion molecules A and 2 (JAMA, JAM2) and the heat shock proteins (HSP70 and HSP90) in the YST and small intestine of embryonic broilers. Broiler eggs were incubated at 37.5°C. On embryonic day 12 (E12), half of the eggs were switched to 39.5°C. YST samples were collected from E7 to day of hatch (DOH), while small intestinal samples were collected from E17 to DOH. The temporal expression of TJ protein mRNA from E7 to DOH at 37.5°C and the effect of incubation temperature from E13 to DOH were analyzed by one-way and two-way ANOVA, respectively and Tukey's test. Significance was set at P < 0.05. The temporal expression pattern of ZO1, OCLN, and CLDN1 mRNA showed a pattern of decreased expression from E7 to E13 followed by an increase to DOH. High incubation temperature caused an upregulation of ZO1 and JAM2 mRNA in the YST and small intestine. Using in situ hybridization, OCLN and JAMA mRNA were detected in the epithelial cells of the YST. In addition, JAMA mRNA was detected in epithelial cells of the small intestine, whereas JAM2 mRNA was detected in the vascular system of the villi and lamina propria. In conclusion, the YST expressed mRNA for TJ proteins and high incubation temperature increased ZO1 and JAM2 mRNA. This suggests that the TJ in the vasculature of the YST and intestine is affected by high incubation temperature.

Reserves of Calcium, Copper, Iron, Potassium, Magnesium, Manganese, Sodium, Phosphorus, Strontium and Zinc in Goose Egg Yolk during Embryo Development.

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.

Effects of 3-Hydroxy-3-methylglutaryl-CoA Reductase Inhibitors on Cholesterol Metabolism in Laying Hens.

This study aimed to investigate the effect of HMGCR inhibitors on egg yolk cholesterol content and its biological mechanisms. Four groups of 180-day-old laying hens (n = 8 cages/group, 6 laying hens/cage) were fed a corn/soybean-based diet (control) and the control diet supplemented with an HMGCR inhibitor at 60, 150, and 300 mg/kg for 4 weeks. The experimental results showed that adding HMGCR inhibitors of 150 mg/kg or more can significantly reduce the cholesterol content in the liver, yolk, serum, and pectoral muscles of laying hens. The RNA-seq results showed that compared with the control group, the addition of HMGCR inhibitors of 150 mg/kg or more to the diet significantly upregulated genes related to cholesterol synthesis in the liver, and the genes involved in steroid synthesis and metabolism, sterol synthesis and metabolism, and cholesterol synthesis and metabolism were all affected by the HMGCR inhibitors. In summary, adding HMGCR inhibitors of 150 mg/kg or more to the diet of hens can significantly reduce the cholesterol content in egg yolk. After the HMGCR inhibitors inhibited the activity of the liver HMGCR, they also altered the expression of genes related to cholesterol synthesis, bile acid synthesis, and cholesterol transport in the liver, and ultimately reduced cholesterol synthesis and cholesterol transport to the egg yolk.

Axenic mass culture of soil-borne nematodes using artificial egg yolk medium

ABSTRACT The amenability to axenic culture in vitro on solid medium including MacConkey, soybean casein, nutrient broth and egg yolk medium of Oscheius tipulae, Caenorhabditis elegans, Acrobeloides tricornis, Acrobeloides bodenheimeri and Teratorhabditis synpapillata were tested using Petri dishes. These nematodes were incapable of growing in MacConkey, soybean casein and nutrient broth, except for C. elegans which was able to multiply in soybean casein medium. While all nematodes used were successfully mass cultured using egg yolk medium at 25°C, results revealed that the highest yield of nematodes was observed with O. tipulae (TC2 and OC2), attaining 176 and 150 k nematodes per plate, respectively, after 10 days post-inoculation. In contrast, the lowest yield was recorded for T. synpapillata. The medium was optimised using different egg yolk concentrations (0, 5, 10, 20 and 40 g/L) and was tested for four nematode species O. tipulae, A. bodenheimeri, A. tricornis and T. synpapillata. The results showed that the egg yolk concentrations and the kinetic of nematode multiplication were positively correlated. Additionally, egg yolk liquid medium was applied to the mass culture of nematodes. Oscheius tipulae, A. bodenheimeri and A. tricornis were capable of reproduction in Petri dishes containing egg yolk liquid medium, at 25°C. Contrarily, T. synpapillata was unable to grow on the same liquid medium. The highest nematode yields of O. tipulae and A. bodenheimeri were attained 10,266 and 4110 nematodes in average, respectively, at 16 days post-inoculation. The maximum multiplication of A. tricornis was recorded at 20 days post-inoculation with 8430 nematodes.

The Effect of Feeding Laying Hens with Nonindustrial Hemp Seed on the Fatty Acid Profile, Cholesterol Level, and Tocopherol Composition of Egg Yolk.

The purpose of this study was to evaluate how cannabis-derived nonindustrial hemp seed (HS) inclusion in laying hen diets, as well as treatment duration, affected the fatty acid (FA) profile, cholesterol level, and tocopherol composition of egg yolks. Ninety-six (n = 96) Lohmann Brown classic laying hens were randomly assigned to one of the four groups: control (standard diet) and HS-containing diets (10% HS, 20% HS, and 30% HS). The study was conducted for a period of 4 months. The findings demonstrated that the FA profile and the tocopherol composition are strongly impacted by the addition of HS to the diet of laying hens (p < 0.05), but the cholesterol content remained unaffected. The increase in the dose of cannabis incorporated into the hen's diet (HS-30% group) led to a significant increase in the amounts of the polyunsaturated fatty acids n-3 and n-6 content of egg yolk. This enrichment was accompanied by a considerable decrease in the n-6/n-3 ratio (p < 0.001) from 8.19 to 4.88, on day 84 of the experiment. The total tocopherol content significantly increased (p < 0.05) from 281.44 (control) to 327.02 μg/g yolk (HS-30%) on day 84. Finally, in the context of warfare, these seeds might be used as a feed additive for laying hens to produce higher nutritive value eggs with affordable prices.

Genotype-dependent impact of dietary vitamin D3 on laying hens

ABSTRACT Vitamin D3 has an integral part in calcium and phosphorus homoeostasis, which in turn plays a key role in egg production of hens. The present study aimed to investigate whether an additional vitamin D3 supplementation improves the laying performance and egg quality of hens according to their genetic potential. For this purpose, four layer lines (low performing: R11 and L68; high performing: WLA and BLA) supplemented either with 300 or 3000 IU vitamin D3 per kg feed were compared concerning serum 25-hydroxyvitamin D3 (25-OHD3), calcium, phosphorus and alkaline phosphatase (ALP), laying performance and egg quality. The higher supplementation of vitamin D3 increased 25-OHD3 serum concentrations in all genotypes, except for R11 and WLA hens in week 49, and also elevated vitamin D3 and 25-OHD3 content in the egg yolk (p < 0.05). In week 29, 3000 IU vitamin D3 decreased pooled least squares means (LSMeans) of serum calcium concentrations considering all genotypes and increased the ALP concentrations in BLA hens (p < 0.05). Considering the whole experimental period daily egg mass of R11 hens was increased by an additional vitamin D3 supplementation (p < 0.001). Regarding all genotypes and the whole experimental period the pooled LSMeans of breaking strength of eggs from hens fed 3000 IU vitamin D3 were higher than those of hens fed 300 IU (p = 0.044). In conclusion, present results give evidence that the higher vitamin D3 supplementation might have genotype-dependently beneficial effects on calcium and phosphorus homoeostasis of hens, which might improve feed efficiency in the early laying period and promote the persistence of the laying period irrespectively of genotype. The increase of serum 25-OHD3 by the higher vitamin D supplementation supported the higher transfer of vitamin D in the egg yolk and improved genotype-dependently the breaking strength of the eggshell.

Egg residue and depletion of meloxicam in Jing Hong laying hens following multiple oral doses

Meloxicam is a nonsteroidal anti-inflammatory drug (NSAID) commonly used in an extra-label manner in commercial laying hens for the treatment of foot lesions, which are a common issue in this species. The present study aimed to determine the depletion profiles of meloxicam in eggs with multiple oral administration under 2 different dosing regimens and to further recommend reasonable withdrawal intervals (WDIs). Meloxicam (1 mg/kg) was administered orally to laying hens under 2 dosing schedules: 10 doses at 24-h intervals and 15 doses at 12-h intervals. Eggs were collected daily after the first dosing, and meloxicam concentrations in both yolk and white were determined by a high-performance liquid chromatography (HPLC) method. The weight ratio of white to yolk in the whole egg was 1.54 (the mean of 20 eggs with repeated tests), and this value combined with the meloxicam concentrations in white and yolk were used to calculate the drug concentrations in whole eggs. Meloxicam was quickly eliminated from egg white, and its concentrations could only be quantified at 2 time points during the elimination phase. The elimination half-lives in yolk and whole egg were 3.07 ± 1.00 and 2.98 ± 0.88 d, respectively, after 10 repeated doses. And the corresponding elimination half-lives were 2.30 ± 0.83 and 2.18 ± 0.67 d, respectively, after repeated 15 doses. Considering the time when meloxicam was not detectable in eggs with the time of ovum development and maturation, a withdrawal interval (WDI) was suggested as 17 d for both dosing schedules. The current results enriched the study on the residue of meloxicam in domestic Jing Hong laying hens and provided WDIs to help ensure animal-derived food safety.

Yolk Fatty Acid Content, Lipid Health Indices, and Oxidative Stability in Eggs of Slow-Growing Sasso Chickens Fed on Flaxseed Supplemented with Plant Polyphenol Extracts.

Previous attempts to increase the level of flaxseed in hens' diet for the production of n-3 polyunsaturated fatty acids (n-3 PUFAs)-enriched eggs have been commonly associated with undesirable effects on production efficiency, lipid health indices, and oxidative stability of eggs, requiring adequate research attention. This study investigated the effects of feeding a moderate level of flaxseed (FS) and plant polyphenol extracts (PPEs) on fatty acid content, oxidative stability, and lipid health indices in eggs of slow-growing Sasso T451A laying hens. One hundred and five hens were assigned to five groups (seven replicates of three) and fed on FS (75 g flaxseed and no antioxidants), VE8 (75 g flaxseed and 800 mg vitamin E), TS8 (75 g flaxseed and 800 mg Thymus schimperi), DA8 (75 g flaxseed and 800 mg Dodonaea angustifolia), and CD8 (75 g flaxseed and 800 mg Curcuma domestica) extract per kg diets. The egg yolk content of eicosapentaenoic acid (EPA, C20:5 n-3) in the DA8, TS8, and CD8 diets and docosahexaenoic acid (DHA, C22:6 n-3) in TS8 and CD8 diets significantly (p < 0.05) increased compared with the FS diet. The FS diet significantly increased the malondialdehyde (MDA) content in egg yolks, whereas the TS8 diet decreased it by 67% (p < 0.05). Little difference was observed in yolk fatty acid content between cooked and raw eggs. Production of n-3 PUFA-enriched eggs with favorable lipid health indices was possible through inclusion of PPEs extracted from local plant species grown in Ethiopia and a moderate dose of flaxseed in the diet of laying hens.

A Comparative Study of Pickled Salted Eggs by Positive and Negative Pressure-Ultrasonic Method

In this study, the positive and negative pressure-ultrasonic method was applied to salted egg pickling, compared with traditional pickled salted eggs by various physical and chemical indicators. Results indicated the salt content of egg white and egg yolk increased rapidly in the salt-preserved salted egg with the positive and negative pressure-ultrasonic method, and the moisture content decreased rapidly. In addition, the oil yield of egg yolk was marinated for 12 days compared with the normal method of 35 days, and the ripening time of salted eggs was shortened by 2/3. There was no obvious difference in the microscopical structure of the egg yolk between the two methods of pickling. Moreover, the pores on the eggshell of the salted egg that was marinated by the positive and negative pressure-ultrasonic method had big cracks, which was beneficial to the substance exchange of the eggs and the outside. The common volatile flavor substances were detected by GC-MS, and a total of 33 flavor constituents were detected. There was no significant difference between the content of alcohols, aldehydes, and ketones, which contributed greatly to the flavor. Overall, the results indicated that this innovative salted eggs method can significantly reduce the curing time while ensuring the quality of salted eggs.

The Efficiency of Urtica dioica Extract in Feeding of Laying Hens

Currently, poultry specialists are working hard to find feed additives of natural origin. Medicinal plants are a source of a wide range of biologically active compounds with multifunctional effects, including antimicrobial ones. To understand the potential use of various medicinal plants and their extracts in poultry farming, the current study aimed to investigate the effect of feeding different doses of water-ethanol extract of Urtica dioica (Urtica dioica L.) on the egg productivity of laying hens. A total of 300 laying hens were divided to control and five experimental groups of chickens, each with 5 replicates. During the entire experiment, the laying hens of the control group were fed complete compound feeds according to the egg-laying phase, and the chickens of the experimental groups were additionally fed Urtica dioica extract in different doses. The results indicated that feeding laying hens with Urtica dioica extract in doses of 5, 10, 15, 20, and 25 mg/kg of body weight had a positive effect on their egg productivity. An increase in egg production per average laying hen in the experimental groups was 2.6-6.1%, and the intensity of egg production was 2.1-5.4%, compared to the control. However, the feed consumption in all experimental groups decreased. When introducing Urtica dioica extract into full-fledged compound feeds for laying hens, there was an increase in the relative egg white content, egg white/egg yolk ratio, and a decrease in relative yolk and shell content. Accordingly, it is suggested to include Urtica dioica extract at a dose of 15 mg/kg in the diet of laying hens which can improve economic efficiency and egg parameters. Keywords: Chemical composition, Egg morphology, Egg production, Feed conversion, Medicinal plant

Identification of candidate genomic regions for egg yolk moisture content based on a genome-wide association study

BackgroundEggs represent important sources of protein and are widely loved by consumers. Egg yolk taste is an important index for egg selection, and the moisture content of the egg yolk affects the taste. To understand the molecular mechanism underlying egg yolk moisture content, this study determined the phenotype and heritability of egg yolk water content and conducted a genome-wide association study (GWAS) using a mixed linear model.ResultsWe determined the phenotype and heritability of thermogelled egg yolk water content (TWC) and found that the average TWC was 47.73%. Moreover, significant variations occurred (41.06–57.12%), and the heritability was 0.11, which indicates medium-low heritability. Through the GWAS, 48 single nucleotide polymorphisms (SNPs) related to TWC (20 significantly, 28 suggestively) were obtained, and they were mainly located on chromosomes 10 and 13. We identified 36 candidate genes based on gene function and found that they were mainly involved in regulating fat, protein, and water content and embryonic development. FGF9, PIAS1, FEM1B, NOX5, GLCE, VDAC1, IGFBP7, and THOC5 were involved in lipid formation and regulation; AP3S2, GNPDA1, HSPA4, AP1B1, CABP7, EEF1D, SYTL3, PPP2CA, SKP1, and UBE2B were involved in protein folding and hydrolysis; and CSF2, SOWAHA, GDF9, FSTL4, RAPGEF6, PAQR5, and ZMAT5 were related to embryonic development and egg production. Moreover, MICU2, ITGA11, WDR76, BLM, ANPEP, TECRL, EWSR1, and P4HA2 were related to yolk quality, while ITGA11, WDR76, BLM, and ANPEP were potentially significantly involved in egg yolk water content and thus deserve further attention and research. In addition, this study identified a 19.31–19.92 Mb genome region on GGA10, and a linkage disequilibrium analysis identified strong correlations within this region. Thus, GGA10 may represent a candidate region for TWC traits.ConclusionThe molecular genetic mechanism involved in TWC was revealed through heritability measurements and GWAS, which identified a series of SNPs, candidate genes, and candidate regions related to TWC. These results provide insights on the molecular mechanism of egg yolk moisture content and may aid in the development of new egg traits.

Effects of different protectants on the IgY content and physico-chemical properties of spray-dried egg yolk powder.

Egg yolk powder (EYP) with high immunoglobulin of yolk (IgY) content and good solubility is in great demand in the market of functional foods. In this article, the properties of spray-dried EYP with the addition of five protectants (maltodextrin, trehalose, mannitol, maltitol and sucrose) were investigated. All the protectants increased IgY activity and solubility of EYP. Among them, EYP with maltodextrin displayed the highest activity of IgY (27.11 mg/g), the highest solubility (66.39%) and the lowest surface hydrophobicity. Moreover, the average particle size of EYP with maltodextrin was the smallest (9.78 μm). The egg yolk particles obtained by adding the protectants are more uniformly distributed and have smaller particle size. Fourier-transform infrared spectroscopy confirmed the structural integrity of the proteins, indicating that the protectants addition enhanced the hydrogen bonding forces between the EYP protein molecules. The addition of protectants can significantly improve the IgY content, solubility and structural stability of EYP. © 2023 Society of Chemical Industry.

Trans-generational physiological condition of embryos is conditioned by maternal thermal stress in Octopus maya

Anthropogenic global warming generates profound metabolic alterations in marine ectotherm invertebrates capable of leading a wide range of these species to extinction. To evaluate the cross-generational effect of thermal stress on the cephalopod Octopus maya, groups of females were exposed at 24 and 30 °C until spawn. After, embryos of each female group were incubated at 24 and 30 °C allowing for evaluating the transgenerational effects on embryos exposed to high and low temperatures. We analyzed the morphology, oxygen consumption, antioxidant mechanisms, and oxidative stress indicators of the embryos. The results demonstrate that thermally stressed females produced smaller eggs with lower yolk content as observed in nonthermally stressed females. Also was observed that embryos from females acclimated at 30 °C had lower body weight and higher respiratory rates when compared with nonthermal stressed females. Embryos from females acclimated at 30 °C showed a collapse of the antioxidant defense system measured as lower both catalase activity and total glutathione concentrations. Additionally, glutathione-s transferase activity increased in embryos incubated at 30 °C and in females maintained at high temperatures in a clear deleterious and cross-generational effect of thermal stress on this octopus species. No changes were observed in the activity of B-esterases in octopus embryos linked with the thermal stress of females. Embryos from thermally stressed females had smaller sizes, less yolk, and higher metabolic rates. Additionally, a collapse in the antioxidant defense system was observed indicating they were unable to control the high load of ROS and oxidative damage, which was partially acquired by maternal inheritance.