Effects of carotenoids from lucerne, marigold and tomato on egg yolk pigmentation and carotenoid composition

Effect of feeding broccoli floret residues on leghorn layer performance and egg quality and nutrient digestibility

1. A study was conducted to determine the effects of dried broccoli floret (DBF) on egg production parameters, egg quality and apparent nutrient digestibility of laying hens. It was hypothesised that feeding DBF can improve egg quality without adversely affecting layer performance.2. Seventy-two White Leghorn layers aged 62 weeks were randomly allotted to 4 dietary treatments (6 cage replicates with 3 hens each) and fed diets containing 0, 40, 80 and 120 g/kg DBF in feed for 56 d.3. Inclusion of DBF had no effect on feed intake, egg production, feed conversion ratio or egg components. However, egg weight increased (linear effect, P < 0.05) as the level of DBF in the diet increased. Egg breakage strength, eggshell strength and Haugh unit were not influenced by dietary treatments. Egg yolk colour (quadratic effect, P = 0.002) and α-tocopherol concentration (quadratic effect, P < 0.0001) improved as a result of DBF inclusion. Egg yolk cholesterol concentration was not altered by DBF inclusion. Apparent total tract nutrient (dry matter, organic matter and crude protein) digestibility coefficients decreased (linear effect, P < 0.05) as the level of DBF increased.4. Feeding DBF to layers up to 120 g/kg of the diet had no negative effects on feed intake, egg production and feed efficiency and improved egg yolk colour and α-tocopherol concentration. However, total tract nutrient digestibility coefficients were negatively decreased as a result of DBF inclusion.

Digestibility, productive performance, and egg quality of laying hens as affected by dried cassava pulp replacement with corn and enzyme supplementation

Two experiments were conducted to investigate the potential use of dried cassava pulp (DCP) supplemented with enzymes as an alternative feed ingredient in laying hen diets. In experiment 1, 45 laying hens (Isa Brown) aged 45 weeks were placed in individual cages to measure nutrient digestibility for 10 days. Nine dietary treatments were control and DCP as a replacement for corn at 20, 25, 30, and 35% supplemented with mixed enzymes (cellulase, glucanase, and xylanase) at 0.10 and 0.15%. Results showed that the use of DCP at 20-35% added with mixed enzymes had no negative effects on dry matter digestibility, while organic matter digestibility and nitrogen retention decreased with increased DCP up to 30-35% in diets. Both enzyme levels (0.10 and 0.15%) showed similar results on nutrient digestibility and retention. In experiment 2, a total of 336 laying hens aged 32 weeks were randomly allocated to seven dietary treatments (control and DCP-substituted diets at 20, 25, and 30%) supplemented with mixed enzymes (0.10 and 0.15%). Diets incorporated with 20-30% of DCP and supplemented with mixed enzymes at both levels had no significant effects on egg production, egg weight, feed intake, egg mass, feed conversion ratio, protein efficiency ratio, or egg quality, except for egg yolk color being decreased with an increase of DCP in diets (P < 0.05). In conclusion, it is suggested that DCP supplemented with enzymes can be used as an energy source in laying hen diets up to 30% without showing negative effects on nutrient digestibility, productive performance, or egg quality.

Preservation of Quality of Table Eggs Using Vegetable Oil and Shea Butter

The poultry industry in Nigeria keeps expanding on a daily basis and it is faced with the problem of egg glut almost yearly. Most of the poultry are raised in rural environments where there is no available and avoidable power supply for egg preservation. The study was aimed at using locally available and cheap materials for preservation of eggs quality under the hot ambient temperature. The eggs were divided into three groups of 80 eggs each. The first and second groups were treated with vegetable oil (soybean oil) and shea butter, respectively, while the third group served as control. The eggs were stored under the ambient conditions and assessed for their physical and nutritional qualities on days 1, 8, 15, 22, 29, 36, 43 and 50. The physical quality was assessed by determining the albumen height and the Haugh’s unit, while the nutritional quality was appraised through the protein concentration of the albumen. Based on the values of Haugh’s unit, eggs treated with vegetable oil produced excellent results; good quality eggs were obtained up to 50th day of storage. Treatment with shea butter maintained quality eggs up to the 29th day, while with untreated eggs good physical quality was maintained up to 22nd day of storage. Protein concentrations of eggs in the three groups studied decline with duration of storage, however the protein concentrations of eggs treated with vegetable oil were significantly higher than the other groups (p<0.001). The eggs treated with shea butter recorded a comparative higher protein concentrations than the untreated eggs (p=0.002).

Yolk vitamin E positively affects prenatal growth but not oxidative status in yellow-legged gull embryos

Parental effects occur whenever the phenotype of parents or the environment that they experience influences the phenotype and fitness of their offspring. In birds, parental effects are often mediated by the size and biochemical quality of the eggs in terms of maternally transferred components. Exogenous antioxidants are key egg components that accomplish crucial physiological functions during early life. Among these, vitamin E plays a vital role during prenatal development when the intense metabolism accompanying rapid embryo growth results in overproduction of pro-oxidant molecules. Studies of captive birds have demonstrated the positive effect of vitamin E supplementation on diverse phenotypic traits of hatchling and adult individuals, but its effects on embryo phenotype has never been investigated neither in captivity nor under a natural selection regime. In the present study, we experimentally tested the effect of the in ovo supplementation of vitamin E on morphological traits and oxidative status of yellow-legged gull (Larus michahellis) embryos. The supplementation of vitamin E promoted somatic growth in embryos soon before hatching, but did not affect their oxidative status. Our results suggest that maternally transferred vitamin E concentrations are optimized to prevent imbalances of oxidative status and the consequent raise of oxidative damage in yellow-legged gull embryos during prenatal development.

Preservation of Quality of Table Eggs Using Vegetable Oil and Shea Butter

The poultry industry in Nigeria keeps expanding on a daily basis and it is faced with the problem of egg glut almost yearly. Most of the poultry are raised in rural environments where there is no available and avoidable power supply for egg preservation. The study was aimed at using locally available and cheap materials for preservation of eggs quality under the hot ambient temperature. The eggs were divided into three groups of 80 eggs each. The first and second groups were treated with vegetable oil (soybean oil) and shea butter, respectively, while the third group served as control. The eggs were stored under the ambient conditions and assessed for their physical and nutritional qualities on days 1, 8, 15, 22, 29, 36, 43 and 50. The physical quality was assessed by determining the albumen height and the Haugh’s unit, while the nutritional quality was appraised through the protein concentration of the albumen. Based on the values of Haugh’s unit, eggs treated with vegetable oil produced excellent results; good quality eggs were obtained up to 50thday of storage. Treatment with shea butter maintained quality eggs up to the 29thday, while with untreated eggs good physical quality was maintained up to 22ndday of storage. Protein concentrations of eggs in the three groups studied decline with duration of storage, however the protein concentrations of eggs treated with vegetable oil were significantly higher than the other groups (p<0.001). The eggs treated with shea butter recorded a comparative higher protein concentrations than the untreated eggs (p=0.002).

Lutein Specific Relationships among Some Spectrophotometric and Colorimetric Parameters of Chicken Egg Yolk

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

Effects of dietary marigold extract supplementation on growth performance, pigmentation, antioxidant capacity and meat quality in broiler chickens

OBJECTIVE

This experiment was conducted to investigate the effects of dietary supplementation with marigold extract on growth performance, pigmentation, antioxidant capacity and meat quality in broiler chickens.

METHODS

A total of 320 one-day-old Arbor Acres chickens were randomly divided into 5 groups with 8 replicates of 8 chickens each. The chickens of control group were fed with basal diet and other experimental groups were fed with basal diet supplemented with 0.075%, 0.15%, 0.30%, and 0.60% marigold extract respectively (the corresponding concentrations of lutein were 15, 30, 60, and 120 mg/kg).

RESULTS

The results showed that marigold extract supplementation increased the yellowness values of shank, beak, skin and muscle and the redness (a*) value of thigh muscle (linear, p<0.01). Marigold extract supplementation significantly increased the total antioxidant capacity, and the activities of superoxide dismutase in liver and thigh muscle (linear, p<0.01) and significantly decreased the malondialdehyde contents of liver and thigh muscle (linear, p<0.01). Marigold extract supplementation significantly decreased the drip loss and shear force of thigh muscles (linear, p<0.01). There was no significant effect on growth performance with marigold extract supplementation.

CONCLUSION

In conclusion, dietary supplementation of marigold extract significantly increased the yellowness values of carcass, antioxidant capacity and meat quality in broiler chickens.

Characterization and safety evaluation of a Deinococcus member as feed additive for hens

As previous studies mainly focus on understanding the mechanisms of radioresistance in Deinococcus bacteria, the present study aimed at characterizing and verifying the safety use of the GKB-Aid 1995 strain, a member of the radiation-resistant bacterial genus Deinococcus, as an ingredient in feed supplements. Using Vitek 2 system and 16S rRNA gene sequencing, GKB-Aid 1995 most resembles Deinococcus grandis. The Ames test, in vitro chromosomal test, in vivo micronucleus test and acute toxicity test were performed subsequently for its safety evaluation. As there is a possibility that the pigment of GKB-Aid 1995 can pass from feed to eggs intended for human consumption, an acute toxicity test was also carried out in pigmented egg yolk. The results confirmed that GKB-Aid 1995 was non-genotoxic in three genotoxicity experiments, and the LD50 of GKB-Aid 1995 and the pigmented egg yolk in ICR mice was greater than 10 and 12 g kg(-1) body weight, respectively. Overall, these data indicate that GKB-Aid 1995 is a non-toxic substance with no genotoxicity and is therefore safe to be used as a feed supplement or feed additive. This study suggests there is potential in developing GKB-Aid 1995 as an animal feed additive intended to enhance yolk coloration to meet the demand of consumers.

Antioxidant systems in chick embryo development. Part 1. Vitamin E, carotenoids and selenium

Chick viability is known to be an important factor determining profitability of the poultry industry. Chick embryo tissues contain a high proportion of highly polyunsaturated fatty acids in the lipid fraction and therefore need antioxidant defence. The antioxidant system of the developing embryo and newly hatched chick includes the antioxidant enzymes (superoxide dismutase, glutathione peroxidase, catalase), water-soluble antioxidants (ascorbic acid, taurine, carnitine, glutathione, etc.), fat-soluble antioxidants (vitamin E, carotenoids, coenzyme Q) as well as selenium (Se). In fact, the high levels of endogenous antioxidants within the egg and embryonic tissues can clearly serve as a major adaptive mechanism for the protection of the tissue during the oxidative stress experienced at hatching. It has been shown that among different nutrients in the maternal diet which could significantly affect chick embryo development and their viability in the early posthatch life, natural antioxidants have been suggested to play a central role. Our data indicate that increased supplementation of the maternal diet can substantially increase concentrations of vitamin E, carotenoids (especially canthaxanthin) and Se in developing chick tissues and significantly decrease susceptibility to lipid peroxidation being effective nutritional tools to deal with various commercial stresses in poultry production.

Hen Egg as an Antioxidant Food Commodity: A Review

Intake of antioxidants through diet is known to be important in reducing oxidative damage in cells and improving human health. Although eggs are known for their exceptional, nutritional quality, they are not generally considered as antioxidant foods. This review aims to establish the importance of eggs as an antioxidant food by summarizing the current knowledge on egg-derived antioxidants. Eggs have various natural occurring compounds including the proteins ovalbumin, ovotransferrin and lysozyme in egg white, as well as phosvitin, carotenoids and free aromatic amino acids in egg yolk. Some lipophilic antioxidants such as vitamin E, carotenoids, selenium, iodine and others can be transferred from feed into egg yolk to produce antioxidant-enriched eggs. The bioactivity of egg antioxidants can be affected by food processing, storage and gastrointestinal digestion. Generally thermal processing methods can promote loss of antioxidant properties in eggs due to oxidation and degradation, whereas gastrointestinal digestion enhances the antioxidant properties, due to the formation of new antioxidants (free amino acids and peptides). In summary, in addition to its well-known nutritional contribution to our diet, this review emphasizes the role of eggs as an important antioxidant food.

Chemical Compositions of Egg Yolks and Egg Quality of Laying Hens Fed Prebiotic, Probiotic, and Synbiotic Diets

A 16-wk feeding experiment was conducted to investigate the effects of a prebiotic, isomaltooligosaccharide (IMO), a probiotic, PrimaLac®, and their combination as a synbiotic on the chemical compositions of egg yolks and the egg quality of laying hens. One hundred and sixty 16-wk-old Hisex Brown pullets were randomly assigned to 4 dietary treatments: (i) basal diet (control), (ii) basal diet + 1% IMO (PRE), (iii) basal diet + 0.1% PrimaLac® (PRO), and (iv) basal diet + 1% IMO + 0.1% PrimaLac® (SYN). PRE, PRO, or SYN supplementation not only significantly (P < 0.05) decreased the egg yolk cholesterol (24- and 28-wk-old) and total saturated fatty acids (SFA; 28-, 32-, and 36-wk-old), but also significantly (P < 0.05) increased total unsaturated fatty acids (UFA; 28-, 32-, and 36-wk-old), total omega 6 and polyunsaturated fatty acids (PUFA), including linoleic and alpha-linolenic acid levels in the eggs (28-wk-old). However, the total lipids, carotenoids, and tocopherols in the egg yolks were similar among all dietary treatments in the 24-, 28-, 32-, and 36-wk-old hens. Egg quality (Haugh unit, relative weights of the albumen and yolk, specific gravity, shell thickness, and yolk color) was not affected by PRE, PRO, or SYN supplementation. The results indicate that supplementations with IMO and PrimaLac® alone or in combination as a synbiotic might be useful for improving the cholesterol content and modifying the fatty acid compositions of egg yolk without affecting the quality of eggs from laying hens between 24 and 36 wk of age.

Effects of dietary supplementation with Gynura procumbens (Merr.) on egg yolk cholesterol, excreta microflora and laying hen performance

Abstract 1. The present study investigated the effects of dietary supplementation with Gynura procumbens on egg yolk and serum cholesterol and triglycerides, excreta microflora, laying performance and egg quality. 2. A total of 160 Hy-Line Brown layers (45 weeks old) were randomly assigned into 4 treatments on the basis of laying performance. Each treatment had 4 replicates with 10 birds each. 3. Dietary treatments were basal diet supplemented with 0 (control), 2.5, 5.0 and 7.5 g/kg diet G. procumbens during 56-d feeding period. 4. Serum (d 21, 42 and 56) and egg yolk (d 28, 42 and 56) cholesterol and triglycerides concentrations were linearly reduced with increasing dietary concentrations of G. procumbens. 5. Increasing dietary concentrations of G. procumbens linearly reduced the excreta total anaerobic bacteria (d 28), Clostridium sp. and Escherichia coli (d 28 and 56) populations. 6. Overall egg production and egg mass were linearly increased, and overall feed efficiency was linearly improved with increase in dietary G. procumbens. 7. Dietary increasing concentrations of G. procumbens linearly improved egg yolk colour (d 28 and 56) and breaking strength of eggs (d 56). 8. The results obtained in the present experiment indicate that dietary supplementation with G. procumbens could reduce the egg yolk cholesterol, suppresses harmful excreta microflora and improves layers performance.

The Effects of Rhodobacter capsulatus KCTC-2583 on Cholesterol Metabolism, Egg Production and Quality Parameters during the Late Laying Periods in Hens

An experiment was conducted to investigate the effects of dietary supplementation of Rhodobacter capsulatus KCTC-2583 on egg-yolk and serum cholesterol, egg production and quality parameters during the late laying periods in hens. A total of 160 Hy-Line Brown layers (54 wk-old) were randomly allotted to 4 treatment groups on the basis of laying performance. Each treatment had 4 replicates with 10 birds each (40 birds per treatment). Two hens were confined individually with cage size 35×35×40 cm and each 10 birds (5 cages) shared a common feed trough between them forming one experimental unit. Dietary treatments were; basal diet supplemented with 0 (control), 0.05, 0.10 and 0.15% R. capsulatus KCTC-2583. Experimental diets were fed in meal form for 56 d. Dietary supplementation of increasing levels of R. capsulatus KCTC-2583 reduced (linear, p<0.05) egg-yolk cholesterol and triglycerides (d 28, 42 and 56) concentrations. Also, serum cholesterol and triglycerides (d 21, 42 and 56) concentrations were linearly reduced (p<0.05) with increasing dietary R. capsulatus KCTC-2583. Laying hens fed a diet supplemented with increasing levels of R. capsulatus KCTC-2583 had increased (linear; p<0.05) overall egg production, egg weight, egg mass and feed efficiency. However, dietary treatments had no effect (linear or quadratic; p>0.05) on feed intake of laying hens. At d 28 and 56, breaking strength and yolk colour of eggs were linearly improved (p<0.05) in laying hens fed dietary increasing levels of R. capsulatus KCTC-2583. Dietary treatment had no effects (linear or quadratic; p>0.05) on albumin height, shell thickness and shell weight at any period of experiment. These results indicate that dietary supplementation of R. capsulatus KCTC-2583 has the potential to improve the laying hen performance and lead to the development of low cholesterol eggs during late laying period in Hy-Line Brown hens.

The Tissue Distribution of Lutein in Laying Hens Fed Lutein Fortified Chlorella and Production of Chicken Eggs Enriched with Lutein

Two experiments were conducted to investigate the dietary effects of conventional or lutein fortified chlorella on lutein absorptions, the tissue distributions and the changes in lutein content of eggs in laying hens. In Exp 1, a total of one hundred and fifty, 70 wk-old Hy-Line brown layers were divided into three groups with five replicates and fed with each experiment diet (control diet, diet with 1% conventional chlorella or lutein fortified chlorella) for 2 wk, respectively. The egg production in groups fed diets containing both chlorella powders were higher than that of the control group (p<0.01). With chlorella supplementations, the yolk color significantly increased, although there were no significant differences in the eggshell qualities. The lutein contents of serum, liver and growing oocytes were greatly increased by feeding conventional or lutein fortified chlorella (p<0.01). In Exp. 2, a total of ninety 60 wk-old Hy-Line brown layers were assigned into three groups with three replicates per group (10 birds per replicate). The birds were fed with one of three experimental diets (0, 0.1 or 0.2% lutein fortified chlorella) for 2 wk, respectively. The egg production was not affected by dietary treatments. The egg weight in the group fed with diet containing 0.2% of lutein fortified chlorella was higher than that of the control (p<0.05). As the dietary chlorella levels increased, the daily egg mass linearly increased, although not significantly. The yolk colors in groups fed diets containing lutein fortified chlorella were dramatically increased as compared to the control (p<0.001). The lutein in chicken eggs significantly increased when fed with 0.2% of lutein fortified chlorella (p<0.01). These results suggested that the dietary lutein derived from chlorella was readily absorbed into the serum and absorbed by the liver with growing oocyte for commercial laying hens. Particularly, the lutein fortified chlorella was a valuable natural source for the production of lutein enriched chicken eggs.

Tomato powder in laying hen diets: effects on concentrations of yolk carotenoids and lipid peroxidation

1. The effects of tomato powder supplementation on performance, egg quality, serum and egg yolk carotenoids, vitamins and malondialdehyde (MDA) concentrations in were investigated in laying hens in mid-lay. 2. A total of 90 laying hens, 49 weeks old, were divided into 3 groups consisting of 6 replicate cages, 5 birds per cage. Birds were randomly fed on one of three diets: basal diet and basal diet added with 5 or 10 g tomato powder per kg diet. 3. As tomato powder concentration increased, there were linear increases in feed intake, egg production, egg weight and yolk colour and a linear decrease in feed conversion. Shell weight, shell thickness and Haugh unit remained unchanged in response to dietary treatments. 4. Concentrations of serum and egg yolk lycopene, β-carotene, lutein and vitamin A increased for both diets including tomato powder, whereas MDA decreased linearly with increasing supplemental tomato powder concentration. 5. Tomato powder supplementation increased egg production persistency and increased carotenoids and vitamin A contents in egg yolk, accompanied by reduced yolk lipid peroxidation.

Hen egg yolk lipid fractions with antiatherogenic properties

Three different types of hen egg yolk, cage-free, organic and daily fresh, were tested for their antiatherogenic properties. Total lipids (TL) of all hen egg yolk samples were extracted by the method of Bligh and Dyer and further separated into total polar lipids (TPL) and total neutral lipids (TNL) by counter current distribution chromatography. TPL and TNL were further separated by preparative thin-layer chromatography (TLC). TL, TPL, TNL and the obtained polar and neutral lipid fractions after TLC separation were tested to determine whether they induce platelet activation or inhibit platelet activating factor (PAF)-induced platelet activation. All three hen egg yolk TL samples possessed strong inhibitory activity against PAF-induced platelet activation that was mainly attributed to TPL, especially to PL fraction 4. Cage-free hen egg yolk exhibited the most potent anti-PAF activity in all lipid classes (TL, TPL and TNL). Thus hen egg yolk contains PAF inhibitors that reinforce their nutritional value in terms of protection against cardiovascular diseases, since PAF is a crucial inflammatory phospholipid mediator that is implicated in the mechanism of atherogenesis.

Effects of broccoli stem and leaf meal on broiler performance, skin pigmentation, antioxidant function, and meat quality

Three hundred sixty 1-d-old Ross 308 male broilers were used to study the effects of broccoli stem and leaf meal (BSLM) on growth performance, skin pigmentation, antioxidant function, and meat quality. The chicks were fed 4 diets containing different levels (0, 4.0, 8.0, and 12.0%) of BSLM as partial replacement for corn and soybean meal for a period of 42 d. The results showed that dietary supplementation of BSLM had no effect (P > 0.05) on growth performance. As compared with control, dietary 4%, 8%, and 12% BSLM increased (P < 0.05) b value (yellowness) both in shank and breast skin, increased (P < 0.05) the concentrations of xanthophylls in abdominal fat and breast skin, improved (P < 0.05) total antioxidant capability, lowered malondialdehyde concentration, and decreased drip loss percentage of breast muscle. Dietary 8% and 12% BSLM decreased (P < 0.05) shank L values (lightness), increased (P < 0.05) shank a value (redness), and increased (P < 0.05) the activities of superoxide dismutase and catalase of breast muscle as compared with control. The results indicated that dietary supplementation of BSLM in broiler chickens improved the poultry products quality with the more skin pigmentation and the less drip loss percentage of breast meat. The more skin pigmentation mainly related to the high amount of xanthophylls in BSLM. The decreased meat drip loss fed BSLM may be caused by the antioxidative function of BSLM.

The effects of kale (Brassica oleracea ssp. acephala), basil (Ocimum basilicum) and thyme (Thymus vulgaris) as forage material in organic egg production on egg quality

1. In organic egg production, forage material as part of the diet for laying hens is mandatory. The purpose of the present study was to examine the effect of feeding with forage materials including maize silage, herbs or kale on egg production and various egg quality parameters of the shell, yolk colour, egg albumen, sensory properties, fatty acid and carotenoid composition of the egg yolk. 2. A total of 5 dietary treatments were tested for 5 weeks, consisting of a basal organic feed plus 120 g/hen.d of the following forage materials: 1) maize silage (control), 2) maize silage incl. 15 g/kg basil, 3) maize silage incl. 30 g/kg basil, 4) maize silage incl. 15 g/kg thyme, or 5) fresh kale leaves. Each was supplied to three replicates of 20 hens. A total of 300 hens was used. 3. Feed intake, forage intake and laying rate did not differ with treatment, but egg weight and egg mass produced increased significantly with the kale treatment. 4. The egg shell strength tended to be higher with the kale treatment, and egg yolk colour was significantly more red with the kale treatment and more yellow with basil and kale treatments. The albumen DM content and albumen gel strength were lowest with the thyme treatment. By sensory evaluation, the kale treatment resulted in eggs with less sulphur aroma, higher yolk colour score, and more sweet and less watery albumen taste. Furthermore, the eggs of the kale treatment had significantly higher lutein and β-carotene content. Also, violaxanthin, an orange xanthophyll, tended to be higher in kale and eggs from hens receiving kale. 5. In conclusion, forage material, especially basil and kale, resulted in increased egg production and eggs of high and differentiable quality.

β-Cryptoxanthin biofortified maize (Zea mays) increases β-cryptoxanthin concentration and enhances the color of chicken egg yolk

The laying hen has a natural ability to deposit carotenoids into its egg yolks, especially the xanthophyll carotenoid lutein that is used commercially as an egg colorant. Can this ability to deposit carotenoids be used to enrich egg yolk provitamin A value? After a 10-d carotenoid depletion period in hens (n = 24), the effects of a 20-d intervention with high-β-cryptoxanthin, high-β-carotene, or typical yellow maize on color and carotenoid profile were compared with the effects of a white maize diet (n = 6/treatment). Eggs were collected every other day and yolks were analyzed by using a portable colorimeter to define the color space and by using an HPLC to determine the carotenoid profile. The high-β-cryptoxanthin and yellow maize increased β-cryptoxanthin in the yolk (0.55 ± 0.08 to 4.20 ± 0.56 nmol/g and 0.55 ± 0.08 to 1.06 ± 0.12 nmol/g, respectively; P < 0.001). Provitamin A equivalents increased in eggs from hens fed high-β-cryptoxanthin maize (P < 0.001) but not the high-β-carotene maize. The color (L*, a*, and b*) assessment of the yolks showed an increase in the high-β-cryptoxanthin treatment for the red-green a* scale (P < 0.001) and a decrease for the light-dark L* scale (P < 0.001). No appreciable change was noted in the yellow-blue b* scale for the high-β-cryptoxanthin treatment; but significant changes were noted for the yellow (P = 0.002) and high-β-carotene maize (P = 0.005) treatments, which were most evident at the end of the washout period with white maize. β-Cryptoxanthin-biofortified maize is a potential vehicle to elevate provitamin A equivalents and to enhance the color of yolks. This could lead to a human health benefit if widely adopted.

Dietary plant bioactives for poultry health and productivity

1. Plants and their biologically active chemical constituents, sometimes called secondary metabolites or bioactives, present numerous opportunities for the improvement of livestock production by inclusion in the diet. 2. Many such plant derived materials have well established therapeutic values in man; however, their potential as feed additives in animal production, particularly of poultry, remains largely unexploited. 3. There is increasing evidence indicating that they can be efficient in controlling diseases, and plant bioactives may also influence production parameters such as feed efficiency and product quality. 4. It has been reported that they may even replicate some of the effects of antibiotic growth promoters, which were banned from use in Europe from 2006. 5. This review assesses the status of plant bioactives in poultry production and their mode of action on avian physiology, particularly in the digestive tract.

Dietary strategies to improve nutritional value, oxidative stability, and sensory properties of poultry products

Consumers demand both safer and more nutritious food products exempt of non-natural origin preservatives or other food additives. In this frame, products with lower fat content and/or a higher ratio in unsaturated fatty acids, especially n-3 fatty acids, are desired because these lipids can help prevent the development of cardiovascular and inflammatory pathologies. The intake of meat products is of interest because they are an excellent source of vitamins and minerals. In addition, the shelf-life of meat products can be extended by the presence of natural antioxidants coming from different sources such as plant extracts. Therefore, different strategies have been studied to improve the nutritional value, oxidative stability, and sensory characteristics of meat products and eggs through different mineral and natural dietary supplements. In comparison to other strategies, dietary supplements present the advantage that first the living animals may efficiently distribute the compounds throughout the tissues and second, the dietary supplementation is safer because the resulting enriched meat products and eggs ensure tolerable amounts in humans. Poultry meats and eggs are widely consumed and their fatty acid profile and tocopherol content can be easily modified through different dietary strategies thus being excellent models to improve their nutritional value and oxidative stability.

Deposition of carotenoids in egg yolk by short-term supplement of coloured carrot (Daucus carota) varieties as forage material for egg-laying hens

BACKGROUND

Supplying egg-laying hens with different forage materials may influence egg production and quality. The aim of this study was to examine the short-term effects of standard feed plus 70 g day(-1) per hen of three coloured carrot varieties (orange, yellow and purple) as forage material in comparison with a standard feed control on egg production, egg yolk colour and deposition of carotenoids in the yolk.

RESULTS

Carrot supplementation reduced feed intakes significantly, but not on a dry matter basis. Orange carrot treatment significantly reduced egg mass production, whereas yellow and purple carrot treatments did not differ from the control. Egg and yolk weights of all carrot-supplemented treatments were significantly lower than those of the control, but yolk percentages were similar. Yolk redness increased significantly in the order control < yellow < orange < purple. A similar trend was seen for yolk yellowness, but yellow and orange carrots reached the same level. Yolk colour and carotenoid contents correlated positively and significantly. In particular, purple carrot treatment increased the yolk content of lutein (>1.5-fold) and beta-carotene (>100-fold) compared with the control.

CONCLUSION

Supplementing the feed of egg-laying hens with coloured carrots efficiently increased yolk colour parameters and carotenoid contents, which gives opportunities for improved nutritional value of eggs from forage material-supplemented hens.