Yolk Antioxidant Research Articles

Effect of using hydroxychloride as a copper source on performance, eggshell quality, tibia properties, mineral excretion, and antioxidant capacity of yolk in layer quails

Abstract This research aimed to examine the impact of varying levels of dietary copper (Cu) hydroxychloride on the performance, egg quality, yolk antioxidant capacity, tibia traits, and mineral excretion in laying quails. 125 female 10-week-old quails were randomly distributed into five experimental groups with five replicates, each consisting of five quails. Five experimental isonitrogenous and isoenergetic diets were designed to contain different Cu hydroxychloride (54% Cu) levels at 7.20 (basal diet), 15, 30, 45 and 60 mg/kg respectively. Quails were fed with trial diets for 12 weeks. Performance, egg production, eggshell quality, and biomechanical traits of the tibia were not impacted (P > 0.005) by variations in dietary Cu levels. Yolk antioxidant capacity, measured as yolk DPPH value, exhibited an increase (P < 0.01) in the high-dose group (60 mg/kg). Regarding tibia mineral concentration, Cu concentration decreased linearly (P < 0.001) with increasing Cu level, manganese and zinc content recorded the highest values in quails that had received 60 mg/kg Cu in the diet (P < 0.01), while the lowest phosphorus content was described for 45 and 60 mg/kg. Contrarily, increases (P < 0.01) in dietary Cu resulted in raised faecal Cu content, while phosphorus, manganese, and zinc, were reduced when Cu was added. It can be inferred that adding Cu to the diet of laying quails would not be necessary, which in turn decreases Cu excretion and prevents substantial environmental harm.

Effects of Supplementing Selenium-Enriched Cardamine violifolia to Laying Hens on Egg Quality and Yolk Antioxidant Capacity during Storage at 4 °C and 25 °C.

Oxidative stress occurs in the process of egg storage. Antioxidants as feed additives can enhance egg quality and extend the shelf life of eggs. Selenium-enriched Cardamine violifolia (SEC) has strongly antioxidant properties. The objective of this study was to assess the effects of dietary supplementation with SEC on egg quality and the yolk antioxidant capacity of eggs stored at 4 °C and 25 °C. Four hundred fifty 65-week-old, Roman hens that were similar in laying rate (90.79 ± 1.69%) and body weight (2.19 ± 0.23 kg) were divided into 5 groups. The birds were fed diets supplemented with 0 mg/kg selenium (Se) (CON), 0.3 mg/kg Se from sodium selenite (SS), 0.3 mg/kg Se from Se-enriched yeast (SEY), 0.3 mg/kg Se for selenium-enriched Cardamine violifolia (SEC) or 0.3 mg/kg Se from Se-enriched Cardamine violifolia and 0.3 mg/kg Se from Se-enriched yeast (SEC + SEY) for 8 weeks. The eggs were collected on the 8th week and were analyzed for egg quality and oxidative stability of yolk during storage at 4 °C or 25 °C for 0, 2, 4, or 6 weeks. Dietary SEC and SEC + SEY supplementation increased the Haugh unit (HU) and albumen foam stability in eggs stored at 4 °C and 25 °C (p < 0.05). SS and SEC supplementation increased the yolk index in eggs stored at 25 °C (p < 0.05). SEC or SEC + SEY slowed down an increase in albumen pH and gel firmness in eggs stored at 4 °C and 25 °C (p < 0.05). Moreover, SEC or SEC + SEY alleviated the increase in malonaldehyde (MDA), and the decrease in total antioxidant capacity (T-AOC) level and total superoxide dismutase (T-SOD) activity in yolks stored at 4 °C and 25 °C (p < 0.05). These results indicate that SEC mitigated egg quality loss and improved the antioxidant capacity of yolks during storage. SEC supplementation would be advantageous to extend the shelf life of eggs.

Comparative Effects of Including Inorganic, Organic, and Hydroxy Zinc Sources on Growth Development, Egg Quality, Mineral Excretion, and Bone Health of Laying Quails.

The purpose of this study was to determine the effects of the dietary addition of zinc (Zn) in the form of sulphate (Zn-S), glycine (Zn-G), and hydroxychloride (Zn-H) on quail performance, eggshell quality, antioxidant status, mineral excretion, biomechanical properties and mineralization of bone. A total of 75 female quails (10-weeks-old) were randomly distributed into 3 groups with 5 replications, each with 5 female quails. Treatment groups were set up by adding Zn-S and Zn-H as the inorganic form and Zn-G as the organic form of zinc to the corn-soybean basal diet (34.14mg/kg Zn) to obtain 50mg/kg Zn and the feeding experiment lasted for 12 weeks. Performance parameters and egg production were not impaired by the Zn source (P > 0.05). The inclusion of Zn-S in the diet produced a reduction in eggshell thickness, while an improvement in yolk antioxidant capacity (measured as MDA concentration) was detected compared to the other Zn sources (P < 0.05). Shear strength and cortical bone area increased (P < 0.05) with Zn-G supplementation, however, the mineral concentration of the tibia was higher (P < 0.01) in those quails who had received Zn-H. Lower levels of mineral excretion were observed in both types of supplementations compared to Zn-S. Therefore, it can be stated that Zn-G or Zn-H supplementation in the diet of laying quails could be an interesting strategy to reduce mineral excretion and improve bone mineralization without affecting performance compared to Zn-S. However, further studies are needed to determine the differences between Zn-G and Zn-H.

The potential of lemon peel powder as an additive in layer quails (Coturnix coturnix Japonica): An experimental study.

The current research intended to examine the impact of dietary lemon peel powder (LPP) on laying quail performance, egg quality criteria, and the antioxidant capacity of the yolk. A total of 120 female Japanese quails (272.6±9.3 g), aged 21 weeks, were allotted to 6 trial groups, each with 5 replicates of 4 quails. Additions of 0, 1, 2, 3, 4, or 5 g/kg of LPP to the basal diet were used to create the treatment groups. Quails were fed ad libitum for 70 days. Neither performance parameters nor egg production was affected by LPP. However, eggshell-breaking strength improved by adding 2 g/kg LPP to the diet, but worsened at 5 g/kg. Moreover, the relative weight of eggshell and yolk L* value decreased with the treatments. Dietary LPP enhanced oxidative stability, reducing malondialdehyde (MDA) and increasing 1,1-diphenyl-2-picrylhydrazyl (DPPH) yolk values. The current study demonstrated that LPP, a safe and easily accessible agricultural by-product, enhanced eggshell quality when it was included in the diet of laying quails at doses of 2 g/kg. In contrast, improvement of yolk antioxidant capacity required increased amounts of LPP (4 g/kg). LPP could be advantageous to animal nutrition as an adequate substitute to reduce waste by-products.

Effects of Enriched-in-Oleuropein Olive Leaf Extract Dietary Supplementation on Egg Quality and Antioxidant Parameters in Laying Hens.

The objective of the present study was to evaluate the effects of an olive leaf extract obtained with an up-to-date laboratory method, when supplemented at different levels in laying hens' diets, on egg quality, egg yolk antioxidant parameters, fatty acid content, and liver pathology characteristics. Thus, 96 laying hens of the ISA-Brown breed were allocated to 48 experimental cages with two hens in each cage, resulting in 12 replicates per treatment. Treatments were: T1 (Control: basal diet); T2 (1% olive leaf extract); T3 (2.5% olive leaf extract); T4 (Positive control: 0.1% encapsulated oregano oil). Eggshell weight and thickness were improved in all treatments compared to the control, with T2 being significantly higher till the end of the experiment (p < 0.001). Egg yolk MDA content was lower for the T2 and T4 groups, while total phenol content and Haugh units were greater in the T2. The most improved fatty acid profile was the one of T3 yolks. The α-tocopherol yolk content was higher in all groups compared to T1. No effect was observed on cholesterol content at any treatment. Based on the findings, it can be inferred that the inclusion of olive leaf extract at a concentration of 1% in the diet leads to enhancements in specific egg quality attributes, accompanied by an augmentation of the antioxidant capacity.

Changes in microbial, chemical, physical and techno-functional properties of liquid egg yolk during hyperbaric storage

The effects of hyperbaric storage (HS) at 200 MPa on the microbial, chemical, physical and techno-functional properties of liquid egg yolk were investigated and compared to refrigeration. Inoculated Salmonella enterica (3.35 ± 0.12 logCFU g−1) and Staphylococcus aureus (2.78 ± 0.19 logCFU g−1) resulted below the detection limit after 24 and 48 h HS, respectively. Liquid egg yolk oxidative status remained unaffected for up to 28 days under pressure, probably due to the presence of egg yolk antioxidants. The decrease in egg yolk denaturation enthalpy and the increase in aromatic amino acid exposure indicated that egg yolk proteins unfolded according to structural changes other than those observed during refrigeration. Liquid egg yolk viscosity progressively increased during HS, eventually leading to gelling. Protein modification did not affect liquid egg yolk foaming and emulsifying properties but impaired its solubility and thermally-induced gelling. HS could be used for microbial decontamination of liquid egg yolk while maintaining oxidative stability and the typical capacity to stabilize foams and emulsions.

Performance, Egg Quality, and Yolk Antioxidant Capacity of the Laying Quail in Response to Dietary Choline Levels.

The current study determined the ideal dose of choline in the diet of laying quails based on egg development, egg quality, and antioxidant capacity. A total of 120 female quails (244.7 ± 10.38 g) were randomly assigned to 6 experimental groups with 5 replicates of 4 quails each. In the 10-week trial, treatment diets were formed by adding 6 choline chloride−60% concentrations providing 1500 (control), 2000, 2500, 3000, 3500, and 4000 mg/kg of choline. The feed intake of quails was quadratically affected (p < 0.05) by the choline level of the diet, in other developmental parameters, and by egg quality among these treatments. The feed intake was reduced to 2500 and 3000 mg/kg levels of choline in the diet compared to the control group. Free radical scavenging capacity (DPPH) of the yolk increased linearly (p < 0.001) with dietary choline levels. In contrast, the thiobarbituric acid reactive substances (TBARS) value decreased as dietary choline levels increased, except for 4000 mg/kg levels. Based on the findings of the current study, 1500 mg/kg of dietary choline is adequate to maintain performance parameters and egg quality in laying quails. However, to increase egg antioxidant capacity, in terms of the DPPH value, the dietary choline dose needs to be increased to 3500 mg/kg.

Maternal Responses in the Face of Infection Risk.

When animals are sick, their physiology and behavior change in ways that can impact their offspring. Research is emerging showing that infection risk alone can also modify the physiology and behavior of healthy animals. If physiological responses to environments with high infection risk take place during reproduction, it is possible that they lead to maternal effects. Understanding whether and how high infection risk triggers maternal effects is important to elucidate how the impacts of infectious agents extend beyond infected individuals and how, in this way, they are even stronger evolutionary forces than already considered. Here, to evaluate the effects of infection risk on maternal responses, we exposed healthy female Japanese quail to either an immune-challenged (lipopolysaccharide [LPS] treated) mate or to a healthy (control) mate. We first assessed how females responded behaviorally to these treatments. Exposure to an immune-challenged or control male was immediately followed by exposure to a healthy male, to determine whether treatment affected paternity allocation. We predicted that females paired with immune-challenged males would avoid and show aggression towards those males, and that paternity would be skewed towards the healthy male. After mating, we collected eggs over a 5-day period. As an additional control, we collected eggs from immune-challenged females mated to healthy males. We tested eggs for fertilization status, embryo sex ratio, as well as albumen corticosterone, lysozyme activity, and ovotransferrin, and yolk antioxidant capacity. We predicted that immune-challenged females would show the strongest changes in the egg and embryo metrics, and that females exposed to immune-challenged males would show intermediate responses. Contrary to our predictions, we found no avoidance of immune-challenged males and no differences in terms of paternity allocation. Immune-challenged females laid fewer eggs, with an almost bimodal distribution of sex ratio for embryos. In this group, albumen ovotransferrin was the lowest, and yolk antioxidant capacity decreased over time, while it increased in the other treatments. No differences in albumen lysozyme were found. Both females that were immune-challenged and those exposed to immune-challenged males deposited progressively more corticosterone in their eggs over time, a pattern opposed to that shown by females exposed to control males. Our results suggest that egg-laying Japanese quail may be able to respond to infection risk, but that additional or prolonged sickness symptoms may be needed for more extensive maternal responses.

Synergy Between Dietary Quercetin and Vitamin E Supplementation in Aged Hen's Diet Improves Hatching Traits, Embryo Quality, and Antioxidant Capacity of Chicks Hatched From Eggs Subjected to Prolonged Storage.

The current study aims to investigate the effects of the synergy between quercetin and vitamin E in aged hen’s diet on hatchability and antioxidant levels of the embryo and newly hatched chicks from prolonged storage eggs. A total of 400 breeder laying hens of 65 weeks of age were selected and randomly divided into 4 groups. Birds were fed a basal diet alone (Control), and basal diets supplemented with quercetin (Q) (0.4 g/kg) and vitamin E (VE) (0.2 g/kg) alone and their combination (0.4 g/kg Q + 0.2 g/kg VE) for 14 weeks, respectively, to determine their effects on yolk antioxidant status, fertility, embryonic mortality, hatchability, antioxidant status of embryonic tissues, as well as the antioxidant status of the newly hatched chicks. The results showed that the hen’s dietary Q + VE increased the yolk weight, as well as increased the antioxidant status of the egg yolk (p < 0.05). Compared with the control group, the supplementation of Q + VE significantly increased the hatchability of set-fertile eggs and decreased early embryonic mortality in eggs stored for 7 and 14 days, respectively (p < 0.05), and also improved the antioxidant capacity of the embryos obtained from eggs stored for 14 days (before incubation) (p < 0.05). Moreover, Q + VE increased the levels of SOD, GSH-Px, T-AOC, T-SOD, and CAT in the liver, heart, and pectoral muscle of the embryo, 1-day-old and 14-day-old chicks (p < 0.05), as well as upregulated the antioxidant related genes (GPx-1, GPx-2, GPx-4, DIO-1, and SOD-1) in the liver of the embryo, 1-day-old and 14-day-old chicks hatched from 14-days storage eggs (p < 0.05). Meanwhile, the MDA levels were decreased by the Q + VE in the embryo and post-hatched chicks (p < 0.05). In conclusion, these findings suggested that maternal dietary Q + VE exerts beneficial synergistic effects on the antioxidant capacity of the egg yolk, embryo, and chicks during prolong egg storage, therefore, Q + VE could be used as a dietary measure to enhance hatchability and chick quality in poultry production.

Green tea powder inclusion promoted hatchability through increased yolk antioxidant activity

Dietary supplementation of green tea powder (GTP) changes egg quality of hens, however, whether these changes affect incubation is still unknown. This study was to compare the proteomic difference of incubated eggs from hens with GTP supplemented or not. Huainan partridge chickens (1,080) at 35 wk of age were allocated into 2 groups, one group fed basal diet (CG) and one group fed basal diet plus 1% GTP (EG). After 4 wk feeding, artificially fertilized eggs were collected for yolk cholesterol determination and incubation. During incubation, 6 embryos from each group were randomly selected in each day for yolk protein extraction and quantification. Yolk cholesterol content was significantly lower, while the hatchability was significantly higher in EG than that of the CG group (P < 0.05). Yolk protein concentration at embryonic days (ED) of 0, 2, 6, and 13 showed significant changes and were selected for proteomic analysis by 2-dimensional gel electrophoresis combined with liquid chromatography-tandem mass spectrometry. Fifty-one differentially expressed (DE) protein spots were identified among different incubation stages between CG and EG group which were mainly classified into vitellogenin, immunoglobulin, and ovoinhibitor, and occupied 45.1, 23.5, and 15.7%, respectively, to the total DE proteins. Ovotransferrin, participated in extracellular sequestering of iron ion process, was significantly lower in EG group than that of the CG group (P < 0.05). Ig light chain precursor (Immunoglobulin) exhibited higher expression at ED6 in EG group as compared with that of the CG group, and was participated in immune response related processes. Ovoinhibitor, mainly involved in protease binding activity, showed lower abundance at ED13 in EG group as compared with that of the CG group. Vitellogenin-3, showed lower expression in EG group as compared with that of the CG group, was mainly participated in lipid transportation and localization according to GO enrichment. Chickens fed diet with GTP provided eggs more antioxidant ability that increased hatchability, indicated that GTP could be considered as additive in breeding layer.

Garlic oil granules coated with enteric polymer: Effects on performance, egg quality, yolk antioxidants, yolk cholesterol, blood biochemistry and hepatic lipid metabolism in laying hens

The effects of dietary garlic oil coated granules (GOCG) on egg production, egg quality, yolk antioxidant capacity, yolk cholesterol, yolk fatty acids, blood biochemistry and hepatic enzyme activities were investigated. Forty 36-week-old Hisex brown laying hens were randomly assigned to one of the five dietary treatment groups including: (1) basal diet+0 g GOCG/kg diet (GOCG0, control), (2) basal diet+7.5 g GOCG/kg diet (GOCG7.5), (3) basal diet+15 g GOCG/kg diet (GOCG15), (4) basal diet+30 g GOCG/kg diet (GOCG30) and (5) basal diet+60 g GOCG/kg diet (GOCG60), for four weeks. It was found that egg production, egg mass and feed conversion ratio (FCR) improved linearly (P < 0.05) with increasing dietary GOCG levels. Egg weight, albumen weight, yolk color intensity and Haugh units increased linearly (P < 0.05) and there were quadratic effects (P < 0.05) on yolk weight, shell weight, shell thickness and albumen pH. Dietary GOCG increased yolk antioxidant capacity measured by the phosphomolybdenum method and lowered thiobarbituric acid reactive substances (TBARS) (linearly, P < 0.05). Significant decreases were especially noted in terms of mg/100 g yolk of yolk cholesterol at 7, 14, and 28 days, and overall (quadratic P < 0.05, linearly P < 0.05, linear and quadratic P < 0.05 and linear and quadratic P < 0.05, respectively). Yolk fatty acid compositions, however, did not differ by treatment. Serum total cholesterol (Total-C) and triglyceride decreased linearly (P < 0.05) at 28 days. Hepatic 3-hydroxy-3-methylglutaryl-CoA reductase (HMGRC) activity due to treatment decreased (linear and quadratic, P < 0.05), but fatty acid synthase (FAS) activity increased linearly (P < 0.05). Pearson's correlations with mg/100 g yolk of yolk cholesterol at 28 days were statistically significant (P < 0.01) for the reduction of HMGCR activity. Hence, based on the minimum content of yolk cholesterol (mg/100 g yolk) and dietary GOCG levels tested, a dietary GOCG30 is recommended, as this had no negative impacts on other important parameters of egg production for consumption.

Suplementasi Sari Belimbing Wuluh (Averrhoa bilimbi L.) dalam Air Minum terhadap Produktivitas Telur Puyuh

Supplementation of Averrhoa bilimbi L. juice which contains vitamin C and organic acid in drinking water has been proposed to reduce the effect of heat stress on the quail layer. So this is expected to increase the productivity of quail and their egg quality. The aim of this research was to determine the effect of A. bilimbi juice supplementation in quail drinking water on quail performance, physical quality of egg, and egg yolk antioxidant level. Two hundred and forty birds aged 4-5 weeks were maintained for 42 days. A Completely Randomized Design was used in this study with 4 treatments. Each treatment has 4 replications and 15 quails in each replications. Addition of Vita Chick (P0) to the drinking water was used as a positive control. The treatments given were the addition of A. bilimbi extract with different levels of 0% (P1), 2.5% (P2), and 5% (P3) respectively. The variables observed were quail performance, physical egg quality, and egg yolk antioxidant levels. The results showed that the physical quality of quail eggs obtained were the weight of albumen and egg shells did not different all treatments. The addition of A. bilimbi juice in drinking water has affected on the weight and percentage of albumen, eggshell, and Haugh Unit. The addition of 2.5% of A.bilimbi juice (P2) had the lowest feed conversion ratio (FCR). However it showed the highest Haugh Unit number of the egg. There was no different effect of the highest dose of A. bilimbi juice (5%, P3) on the egg yolk antioxidant activity and capacity (41.54% and 23.91 ppm respectively). It was concluded that supplementation of A. bilimbi juice in drinker water could changed to antistress drug commercial.

Effects of selenium and flaxseed on selenium content and antioxidant properties of eggs and immune response in hens

This study aimed to evaluate effects of supplementing the diets of laying hens with different sources of Se and different levels of flaxseed on egg Se concentration, yolk antioxidant properties and immune response. In a completely randomized design, 384 Hy-Line W-36 hens (aged 50 weeks) were assigned to a 3 × 4 factorial arrangement, comprising four replicates of eight hens. For 10 weeks, the birds were fed one of three basal diets containing 0, 50, and 100 g/kg of flaxseed and regular Se content from mineral premix, supplemented with no additional Se (SN) and 1 mg/kg of Se from sodium selenite (SS), Se-enriched yeast (SY), and hydroxy selenomethionine (SOH). The greatest Se concentration in the yolk was observed in diets containing organic Se sources. The SOH diet produced the greatest albumen Se concentration, followed by SY, and then SS. Using any Se supplementation improved glutathione peroxidase activity and total antioxidant capacity, compared with SN. However, superoxide dismutase activity and malondialdehyde were not affected by Se supplementation. Cell-mediated immune response was improved by Se supplementation, especially SS. Antibody response against sheep red blood cell (SRBC) was not affected by Se source, except that IgM was greater in the hens that received SS and SY. Neither flaxseed supplementation, nor its interaction with Se source was significant for any trait. Thus, supplementation of diets with 1 mg/kg Se, especially from organic sources, enriched the egg and improved some yolk antioxidant properties and immune system function. Supplemental flaxseed did not influence any measured traits. Keywords: egg albumin, egg yolk, Immune function, inorganic selenium, organic selenium

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.

Effects of Ginger (Zingiber officinale, Roscoe) Essential Oil on Growth and Laying Performances, Serum Metabolites, and Egg Yolk Antioxidant and Cholesterol Status in Laying Japanese Quail.

This study aimed to investigate the effect of ginger (Zingiber officinale, Rosc.) essential oil on growth and laying performances, egg yolk antioxidant and cholesterol status, and serum metabolites in Japanese quail. Eighty 3-week-old Japanese quails weighing between 120 and 130 g were equally and randomly assigned to four groups receiving daily and orally, respectively, 100 µl/kg body weight (bw) distilled water and 50, 100, and 150 µl/kg bw of ginger rhizomes essential oil, respectively. The entire feeding trial for all groups lasted for 9 weeks and the Z. officinale essential oil effects were studied on growth and laying performances, serum metabolites, and egg yolk antioxidant and cholesterol status. Results revealed that feed intake, live and body weights gain, feed conversion ratio, egg production, and weekly mass of eggs were not significantly (P>0.05) influenced by oral administration of ginger rhizomes essential oil. Unlike the abdominal fat weight which decreased significantly (p<0.05) in all treated quails, the oral administration of ginger rhizomes essential oil had no significant effects (p> 0.05) on liver, intestine, heart, and gizzard relative weights as compared to the control. Egg weight markedly (P<0.05) increased in Japanese quails treated with ginger rhizomes essential oil whatever the dose with reference to the control. The serum content in total cholesterol, LDL-cholesterol, and transaminases (AST and ALT) decreased significantly (P<0.05) with 100 and 150 µl/kg bw of ginger rhizomes essential oil compared to control group. In conclusion, oral administration of 100 to 150 µl/kg bw of ginger rhizomes essential oil to laying Japanese quails positively influences egg weight and decreased serum and egg cholesterols without any adverse effect on feed intake and body weight gain.

In ovo yolk carotenoid and testosterone levels interactively influence female transfer of yolk antioxidants to her eggs.

Mothers can influence prenatal conditions by varying the amount of nutrients, hormones or antioxidants they provide to their developing young. Some of these substances even affect the transfer of these compounds in the next generation, but it is less clear how different maternally transmitted compounds interact with each other to shape reproductive resource allocation in their offspring. Here, we found that female Japanese quails (Coturnix japonica) that were exposed to high carotenoid levels during embryonic development transferred lower concentrations of yolk antioxidants to their own eggs later in life. This effect disappeared when both testosterone and carotenoid concentrations were manipulated simultaneously, showing long-term and interactive effects of these maternally derived egg components on a female's own egg composition. Given that exposure to high levels of testosterone during embryo development stimulates the production of reactive oxygen species (ROS) and impairs antioxidant defenses, we propose that carotenoids act as in ovo antioxidants in an oxidatively stressful environment (i.e. when levels of testosterone are high) but might have prooxidant properties in an environment where they are not used to counteract an increased production of ROS. In line with this hypothesis, we previously showed that prenatal exposure to increased concentrations of yolk carotenoids leads to a rise of oxidative damage at adulthood, but only when yolk testosterone concentrations were not experimentally increased as well. As a consequence, antioxidants in the body may be used to limit oxidative damage in females exposed to high levels of carotenoids during development (but not in females exposed to increased levels of both carotenoids and testosterone), resulting in lower amounts of antioxidants being available for deposition into eggs. Since prenatal antioxidant exposure is known to influence fitness-related traits, the effect detected in this study might have transgenerational consequences.

Maternally derived yolk antioxidants buffer the developing avian embryo against oxidative stress induced by hyperoxia.

In oviparous animals, maternally transferred antioxidants protect the embryo from oxidative damage from high rates of reactive oxygen species (ROS) production incurred by rapid growth. Elevated ROS exposure, beyond that incurred by normal growth, can occur as a result of exposure to exogenous factors (e.g. pollutants, toxins, radiation), increasing the risk of oxidative damage, with potentially adverse consequences for embryonic development and long-term fitness. The capacity of the avian embryo's antioxidant protection system to counter an increased exogenous oxidative threat is poorly understood. We induced an external oxidative challenge via experimental increase in ambient oxygen concentration throughout incubation of wild great tit Parus major eggs in the laboratory. At day 11 of incubation, brain tissue revealed no consistent differences in oxidative stress status [as measured by antioxidant levels (superoxide dismutase and total glutathione), lipid peroxidation and telomere length] between control (21% oxygen) and hyperoxic (40% oxygen) embryos. However, the level of vitamin E was significantly lower and lipid peroxidation was significantly higher in yolks of eggs reared under elevated oxygen concentrations. The results suggest that maternally derived yolk antioxidants successfully buffer developing embryonic tissues against an increased exogenous oxidative threat. Furthermore, vitamin E plays a more important role in protecting the embryo than carotenoids. However, the depletion of antioxidants and increased peroxidation of lipids in the yolk could have negative consequences for embryonic development, in particular for the brain and heart that require highly unsaturated fatty acids, and protection against the oxidative burst following hatching.

Antioxidants and embryo phenotype: is there experimental evidence for strong integration of the antioxidant system?

Organisms have evolved complex defense systems against oxidative stress. Bird eggs contain maternally derived antioxidants that protect embryos from oxidative damage. The antioxidant system components are thought to be integrated, but few studies have analyzed the covariation between antioxidant concentrations, embryo 'oxidative status' and morphology. In addition, no study has tested the effects of experimental change in yolk antioxidant concentration on other antioxidants, on their reciprocal relationships and on their relationships with embryo oxidative status or growth, which are expected if antioxidants defenses are integrated. In yellow-legged gull (Larus michahellis) embryos, we analyzed the covariation between several antioxidants, markers of 'oxidative status' [total antioxidant capacity (TAC), concentration of pro-oxidants (TOS), lipid peroxidation (LPO) and protein carbonylation (PC)] in the yolk, liver and brain, and morphology. Yolk and liver antioxidant concentrations were positively correlated reciprocally and with embryo size, and positively predicted TAC but not oxidative status. TOS and LPO were positively correlated in the liver, while TAC and LPO were negatively correlated in the brain. Weak relationships existed between antioxidants and TOS, PC and LPO. The effects of antioxidants on oxidative status and morphology were non-synergistic. An experimental physiological increase in yolk vitamin E had very weak effects on the relationships between other antioxidants or oxidative status and vitamin E concentration, the concentration of other antioxidants or oxidative status; the covariation between other antioxidants and oxidative status, and relationships between morphology or oxidative status and other antioxidants, challenging the common wisdom of strong functional relationships among antioxidants, at least for embryos in the wild.

Study of the Effects of Dietary Supplementation of Linseeds, Fenugreek Seeds and Tomato-Pepper Mix on Laying Hens Performances, Egg Yolk Lipids and Antioxidants Profiles and Lipid Oxidation Status

This study aimed at improving the egg quality through cholesterol reduction and enrichment with natural pigments, which could prevent lipids oxidation. Eighty 27 week-old Novogen White laying hens were divided into four groups and given 100 g/hen/d of a standard diet (Control, C), standard diet containing 4.5% ground linseed (Linseed diet, L), linseed diet containing 1% dried tomato and 1% sweet pepper (LTP) or linseed diet containing 2% ground fenugreek (LF). LTP and LF were associated with higher feed consumption (P 0.05) by dietary treatment. LF was associated with lower (P 0.05). Egg yolks carotenoids concentrations in yolks from hens on L and LTP diets were not different (P>0.05) and both were higher (P 0.05) and both were higher (P 0.05) by dietary treatment. Egg yolks antioxidant activity of the C groups was lower (P 0.05). There was a significant enrichment of eggs with carotenoids and an enhancement of their antioxidant status in response to linseed supplementation. There was no beneficial effect of further supplementation with sweet red pepper and dried tomato or fenugreek seed. Further investigations are needed to evaluate the impact of these supplements on fatty acids profile and lipid oxidation status of eggs after their storage.

Egg production performance, egg yolk antioxidant profile and excreta concentration of corticosterone in golden pheasants (Chrysolophus pictus) fed diets containing different levels of green vegetables.

In order to study the effect of feeding graded levels of green vegetables on egg production performance and egg yolk antioxidant status, 27 female golden pheasants (GP) were randomly distributed into three groups of nine each in an experiment based on completely randomized design. The diets of the birds in groups T1 , T2 and T3 contained 1.4%, 2.7% and 5.0% of green vegetables respectively. Feeding of experimental diets started on 12th February (day 1) and was continued till 30 June 2012. Average number of eggs laid and egg mass produced by the hens in group T3 was higher (p<0.004) than those of T1 and T2 . Hen day egg production was lowest (p<0.001) in group T1 . Roche yolk colour score was highest (p<0.01) in T3 followed by T2 and was lowest in T1 . Other external and internal egg quality parameters were similar among the groups. Total antioxidant capacity (TAC) of egg yolk was higher (p<0.04) in group T3 as compared to other two groups. Egg yolk concentration of total carotenoids, β-carotene, total sulfhydryl, protein-bound sulfhydryl and non-protein-bound sulfhydryl was higher (p<0.05), whereas concentration of malondialdehyde was lower (p<0.024) in group T3 as compared to other two groups. Excreta concentration of corticosterone washighest (p<0.012) in T1 , followed by T2 , and was lowest in T3 . Egg yolk concentration of TAC and TSH was positively and that of malondialdehyde was negatively correlated with carotenoids intake. Excreta concentration of corticosterone was negatively correlated with carotenoids intake. It was concluded that incorporation of green vegetables in the diet at 5% on dry matter basis would improve egg production, egg yolk antioxidant status and the ability of the captive GP to combat stress.