叶黄素对蛋鸡应用效果的研究

将144只52周龄绿壳商品产蛋鸡随机分为6组,各组在相同日粮基础上分别添加0、20、40、60、80、100mg/kg叶黄素,探讨叶黄素在蛋黄中的沉积规律以及对蛋黄色泽和蛋鸡生产性能的影响。结果说明,蛋黄中叶黄素的含量随日粮中叶黄素添加水平的增加而提高,最大沉积量达1.09mg/60g,是对照组0.23mg/60g的近5倍;日粮中叶黄素能显著(P<0.05)提高蛋黄的罗氏等级(RCF),降低亮值(L),提高红值(a),对黄值(b)无显著影响(P>0.05);日粮中添加高水平叶黄素对蛋鸡生产性能无显著影响(P>0.05)。     

Comparative evaluation of the effect of two maternal diets on fatty acids, vitamin E and carotenoids in the chick embryo.

1. The fatty acid profile of egg yolk and vitamin E and carotenoid accumulation in the egg yolk and embryonic tissues were investigated in relation to the maternal diet. 2. Two hundred fertile eggs (Ross 308 Broiler Breeder), obtained from hens fed on a maize-based (M-diet) or a wheat-based diet (W-diet), were incubated using standard conditions. 3. The egg yolk and embryo tissues (residual yolk, yolk sac membrane, liver, kidney, lung, muscles, adipose tissue and plasma) were collected on d 18 of incubation and on d 21 (newly-hatched chicks) and analysed for fatty acids, vitamin E and carotenoids. 4. The diets did not differ in terms of fatty acid or alpha-tocopherol concentrations. The concentration of carotenoids in the M-diet was 11.8 mg/kg and in the W-diet was 5.6 mg/kg with lutein and zeaxanthin being major carotenoids. 5. Eggs from the M-group contained higher (P<0.01) concentrations of beta+gamma-tocopherols, total carotenoids, lutein and zeaxanthin. Chickens hatched from those eggs were characterised by the increased concentrations of total carotenoids and zeaxanthin in all the tissues studied. The concentration of beta+gamma-tocopherol was enhanced only in the liver and yolk sac membrane. 6. It is concluded that the maternal diet plays an important role in antioxidant systems formation during chick embryonic development; the M-diet can increase the antioxidant potential of the egg yolk and embryonic tissues compared to the antioxidant potential provided by parent birds fed the W-diet.     

Chromatographic analysis of lypophilic compounds in eggs from organically fed hens

Egg yolks represent a common foodstuff in the human diet and are an important source of nutrients including lipids and carotenoids. The aim of this study was to compare the carotenoid, fatty acid and vitamin E contents of the yolk of eggs from nine hen breeds (Barred Plymouth Rock, Speckled Italian, Black Italian, Red Italian, Rhode Island, Silver Laced Wyandotte, Gold Araucana, Partridge Brahma and Yellow Cochin) raised in barns in an enclosed house. Gas chromatography-mass spectrometry (GC-MS) was used for the fatty acid analyses, and reversed phase-high performance liquid chromatography-photodiode array detection (RP-HPLC-PDA) for carotenoids and vitamin E quantification. The major carotenoids identified were lutein and zeaxanthin, which together represented more than 93% of the total carotenoids, followed by β-cryptoxanthin and β-carotene.The results indicated that the total carotenoid content of the eggs ranged from 16.84–87.31 μg/g egg yolk (average value 49 μg/g egg yolk). The most representative fatty acids found were palmitic acid, stearic acid, oleic acid and linoleic acid. Significant differences in the proportions of α-linolenic acid were observed among the samples. The α-tocopherol content was directly correlated with the total carotenoid content. The results show that the chemical composition of egg yolk varies greatly among hen breeds.     

Effect of dietary α‐tocopherol on the bioavailability of lutein in laying hen

Lutein and its isomer zeaxanthin have gained considerable interest as possible nutritional ingredient in the prevention of age‐related macular degeneration (AMD) in humans. Egg yolk is a rich source of these carotenoids. As an oxidative sensitive component, antioxidants such as α‐tocopherol (T) might contribute to an improved accumulation in egg yolk. To test this, chickens were fed lutein esters (LE) with and without α‐tocopherol as an antioxidant. After depletion on a wheat–soya bean‐based lutein‐poor diet for 21 days, laying hens (n = 42) were equally divided into three groups and fed the following diets for 21 days: control (basal diet), a LE group (40 mg LE/kg feed) and LE + T group (40 mg LE plus 100 mg T/kg feed). Eggs and blood were collected periodically. Carotenoids and α‐tocopherol in yolk and blood plasma were determined by HPLC. Egg yolk was also analysed for total carotenoids using a one‐step spectrophotometric method (iCheck^(?)). Lutein, zeaxanthin, α‐tocopherol and total carotenoids in egg yolk were highest after 14 days of feeding and decreased slightly afterwards. At the end of the trial, eggs of LE + T group contained higher amount of lutein (13.72), zeaxanthin (0.65), α‐tocopherol (297.40) and total carotenoids (21.6) compared to the LE group (10.96, 0.55, 205.20 and 18.0 mg/kg, respectively, p < 0.05). Blood plasma values of LE + T group contain higher lutein (1.3), zeaxanthin (0.06) and tocopherol (20.1) compared to LE group (1.02, 0.04 and 14.90 mg/l, respectively, p < 0.05). In conclusion, dietary α‐tocopherol enhances bioavailability of lutein reflecting higher content in egg yolk and blood plasma. Improved bioavailability might be due to increased absorption of lutein in the presence of tocopherol and/or a greater stability of lutein/zeaxanthin due to the presence of α‐tocopherol as an antioxidant.     

Comparative Pigmentation Efficiency of High Dietary Levels of Apo-Ester and Marigold Extract on Quality Traits of Whole Liquid Egg of Two Strains of Laying Hens

This trial was carried out to compare the effect of the dietary supplementation of high doses of either synthetic pigment ethyl ester of β-apo-8′-carotenoic acid (apo-ester) or natural pigments, mainly lutein and zeaxanthin, extracted from Tagetes erecta, on egg quality of hens laying brown shell eggs (ISA Brown) and white shell eggs (Hy-Line White W-36). The hens of each strain were divided into 6 groups and fed a corn-soybean basal diet supplemented either with 40, 60, and 80 ppm of apo-ester (APO) or with 120, 180, and 240 ppm of marigold extract (MAR). Egg pigmentation rose linearly and significantly (P < 0.01) as the dietary levels of apo-ester increased, but this did not occur when MAR supplementation was used. The amount of β-carotene equivalents in whole liquid egg of MAR treatments was almost constant with varying pigment dietary dose and was significantly lower (P < 0.01) than in APO treatments. In both hen strains, whole liquid egg redness (a*) and yellowness (b*) were higher with APO supplementation. The egg component weights were highly affected (P < 0.01) by the hen strain, with yolk:egg ratio higher in the Hy-Line. The trial confirms that in spite of the higher level of MAR supplementation, APO has a better efficiency in whole liquid egg pigmentation. The ISA Brown hens showed a better ability to absorb dietary carotenoids than did the Hy-Line White.     

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.     

Lipid profile in eggs of Araucana hens compared with Lohmann Selected Leghorn and ISA Brown hens given diets with different fat sources

1. In a cross-over trial, the egg cholesterol and fatty acid composition of Araucana hens was compared with those of two commercial breeds (Lohmann Selected Leghorn and ISA Brown) under two feeding regimes, either high (Hn-3) or low (Ln-3) in long-chain n-3 fatty acids. 2. The Hn-3 diet was formed by isocaloric substitution of animal fat in the control diet (Ln-3) by a dry product containing stabilised fish oil with standardised concentrations of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). 3. Both breed and diet had influences on egg composition, without interactions. 4. The Araucana breed showed lower feed intake and lower egg weights than the other two breeds. The yolk weight was similar, leading to a much higher yolk:albumen ratio in the Araucana eggs. 5. In comparison to commercial breeds, Araucanas produced eggs with higher cholesterol content per g of yolk, which was even more pronounced when expressed per g of egg, due to the high yolk content of the eggs. The cholesterol content of an egg remained unchanged by the diet, irrespective of the dietary fat source. 6. Changing to the Hn-3 diet led to greater concentrations of polyunsaturated fatty acids (PUFA) and lower concentrations of monounsaturated fatty acids (MUFA) contents in the yolk, without a change in the ratio of saturated (SFA) to unsaturated fatty acids (UFA). 7. Within the PUFA, the n-3 fatty acids increased at the expense of the n-6 fatty acids, indicating a competition between n-3 and n-6 fatty acids for incorporation in the yolk.     

Optimizing xanthophyll concentrations in diets to obtain well-pigmented yolks

The color of the egg yolk depends on the absorption and deposition of the carotenoids in the hen diet and represents a visual characteristic of great effect on the product acceptance. Corn is commonly used as an energy value ingredient for the hen diet formulations, but its pigmenting potential should also be considered for egg yolk color. The objective of this research was to optimize the proportions between yellow and red carotenoids in corn-based rations to provide the maximization of a yolk's color. For our study, Dekalb laying hens were individually allotted in cages to receive the 15 experimental diets defined by means of a central composite design in which the variables were the yellow xanthoplhylls from the diets (yellow corn + corn gluten meal), the yellow supplementary xanthoplhylls (lutein + zeaxanthin), and the red supplementary xanthoplhylls (cantaxanthin) at 3 concentrations each. Production traits were not influenced by treatments. Seven distinct colors were identified with the yolk color fan; the preferred one (9) was provided by the highest yellow pigment concentrations with no red pigments, whereas the most rejected one (14) was provided by the highest concentration of red pigment. The objective color was derived from the interaction between yellow and red xanthophylls, with an important effect of red supplementary xanthophylls on redness. Using response surface analyses, 0.5 mg/hen per day of red pigments and 1.5 mg/hen per day of total yellow pigments were enough to reach maximum redness (color index 14), whereas 2.0 mg/hen per day of total yellow xanthophylls were enough to reach local consumer preference (color index 9).     

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

1. The effects of various sources of natural carotenoids (Px alfalfa concentrate, tomato powder and marigold extract) as feed additives in quail diets on egg yolk pigmentation and carotenoid composition were investigated. 2. Adult Japanese quail were fed one of 5 different diets for 23 d: three diets each contained Px alfalfa concentrate (PX) or tomato powder (TP) or marigold extract (MG), one diet contained marigold extract and tomato powder (MG + TP) and a control diet (wheat/barley based) was low in carotenoid. All products were added at a rate of 2%, apart from marigold extract which was added at a rate of 0.2%. 3. Visual assessment of yolk colour (Roche colour fan) showed a stabilised yolk colour of 1.6, 7.7, 8.5, 8.8 and 10.6 for the control, PX, TP, MG and MG + TP treatments, respectively. 4. The total carotenoid concentration of the egg yolks were 2.2, 22.4, 4.1, 39.0 and 37.7 microg/g for the experimental groups fed the following diets: control, PX, TP, MG and MG + TP, respectively. Deposition of retinol, alpha-tocopherol and gamma-tocopherol in the egg yolk was unaffected by treatments. 5. Lutein was shown to be the major carotenoid in the egg yolk, comprising 1.65, 17.97, 2.03, 31.14 and 28.57 microg/g in control, PX, TP, MG and MG + TP, respectively. Inclusion of TP in the quail diet resulted in lycopene transfer to the egg. 6. It was concluded that, in comparison with the control group, there was an increase in the yolk concentrations of lutein, zeaxanthin, lycopene and beta-carotene in eggs produced by female quail fed diets supplemented with natural carotenoids.     

Dietary Supplementation with Microencapsulated Lutein Improves Yolk Color and Lutein Content in Fresh and Cooked Eggs of Laying Hens

This study was conducted to compare the efficacy of diet supplemented with non-microencapsulated lutein (NL) and microencapsulated lutein (ML) in laying hens. A total of 270 Hy-line Brown laying hens (54 weeks old) were allocated to three groups with six replicates of 15 hens and were adapted to a wheat-soybean meal basal diet for two weeks. Next, the control birds were fed the basal diet, and the test birds were fed the basal diet supplemented with 600 mg/kg NL (12 mg/kg available lutein) or 90.1 mg/kg ML (10 mg/kg available lutein) for 35 days. Supplementation of lutein did not affect the productive performance of laying hens, but improved (P<0.05) the yolk color and red/green value (a*), with eggs from the ML group displaying improved color and a* values from the 15^th day of the experimental period. The blue/yellow value (b*) for the yolk showed an increase (P<0.05) through both NL and ML supplements. The yolk color of fried and boiled eggs and a* value of the yolk in fried eggs were improved (P<0.05) only through ML supplemented diet. Both NL and ML supplements resulted in lower (P<0.05) lightness and higher (P<0.05) a* values of yolk in boiled eggs, as well as higher (P<0.05) b* values in fried and boiled eggs. Yolk lutein content in fresh, fried, and boiled eggs was increased (P<0.05) in NL and ML groups with the latter being higher. In conclusion, ML improved yolk pigmentation and lutein retention in laying hens better than NL.     

蛋鸡小麦型日粮中添加叶黄素对鸡蛋品质的影响

将360只48周龄“尼克红”蛋鸡随机分为5组,每组设3个重复,每个重复24只。试验1组为玉米基础日粮组,试验2组为小麦型基础日粮组（0．10％酶制剂组）,试验3组为0．10％酶制剂组＋0．5％叶黄素添加剂,试验4组为0．10％酶制剂组＋1．0％叶黄素添加剂,试验5组为0．10％酶制剂组＋1．5％叶黄素添加剂。预试期7天,试验期21天。结果表明,添加1．5％的叶黄素添加剂可以显著改善鸡蛋的蛋黄颜色。与小麦对照组相比,蛋黄颜色提高了188．33%（P〈0．05）。与玉米基础日粮组相比,日粮添加1．5%叶黄素添加剂组鸡蛋蛋黄颜色提高了0．82％,但差异不显著（P〉0．05）,添加叶黄素添加剂对鸡蛋的蛋重、蛋比重、蛋形指数影响不大。     

不同来源色素对蛋黄颜色及叶黄素沉积的影响

为研究不同蛋鸡日粮类型中添加不同来源色素对蛋黄着色及叶黄素沉积的影响,试验1在玉米-豆粕日粮中添加天然或合成虾青素,测定蛋黄色度值(RYCF)和蛋黄中叶黄素含量;试验2在玉米-豆粕和小麦-豆粕日粮中添加混合天然色素(橙黄素∶辣椒红素=1∶1),测定RYCF及叶黄素含量。结果显示:天然虾青素对蛋黄着色无显著影响(P>0.05);合成虾青素可以显著提高RYCF(P<0.05)。不同来源虾青素对叶黄素的沉积无显著影响(P>0.05)。小麦日粮中添加混合天然色素可以显著提高蛋黄叶黄素含量和RYCF(P<0.05),且RYCF与蛋黄叶黄素含量有极显著的相关关系(P<0.01)。对混合色素添加量与RYCF进行拟合,预测RYCF达到8时,需添加混合天然色素2 340 mg/kg。结果表明:合成色素不会增加蛋黄叶黄素含量。在小麦-豆粕基础中添加1.2 g/kg的天然色素可以改善蛋黄色泽,若使RYCF达到8则需添加混合色素2 662 mg/kg。     

Effects of Adding Marine Biological Fortified Material to Diets on Egg Quality

The experiment was aimed to study the effects of adding marine biological fortified material to diets on egg quality.600 healthy Highland Brown egg-shell chicken were chosen and randomly divided into control group and experimental group. The chicken in control group were fed with Jiuzhou diets and that in experimental group were fed with Jiuzhou diets supplemented with marine biological fortified material,and the egg quality and nutrient components such as amino acids,fatty acids and carotenoids were compared.The experiment lasted for 56 d. The results showed that the yolk color of marine vitalized egg was orange-red to bright red,and the ordinary yolk color was yellow. The ratio of yolk weight to egg white weight of the marine vitalized egg was 0.424,which was much higher than that of ordinary egg (0.365).The total amino acids content of the marine vitalized egg achieved 13.22 g/100 g,and the contents of essential amino acids were higher than ordinary egg in different degrees. The percentage of polyunsaturated fatty acids of the marine vitalized egg was 30.53%,meanwhile,the content of carotenoids was 0.75 mg per egg,which were significantly higher than that in ordinary egg (0.52 mg per egg)(P<0.05).The astaxanthin was only detected in the marine vitalized egg,and the ratio of lutein to zeaxanthin was 1.12. The content of organic selenium was about 290 to 490 μg/kg in the marine vitalized egg. These results suggested that marine biological fortified material supplenmentary diets could comprehensively improve the egg quality and nutrition.     

饲料中添加海洋生物营养强化剂对蛋品质的影响

试验旨在研究饲料中添加海洋生物营养强化剂对鸡蛋蛋品质的影响,将600只健康海兰褐壳蛋鸡随机分为两组,分别饲喂普通九洲鸡饲料和含有海洋生物营养强化剂的九洲鸡饲料,对比分析其鸡蛋蛋品质及其功能性营养物质（必需氨基酸、脂肪酸及类胡萝卜素）的变化,试验期56 d。结果显示,试验组海兰褐壳蛋鸡所产鸡蛋（海洋生命蛋）的蛋黄颜色为橙红到鲜红色,蛋黄重/蛋清重为0.424,而普通鸡蛋的蛋黄为黄色和橘黄色,蛋黄重/蛋清重为0.365。海洋生命蛋的总氨基酸含量为13.22 g/100 g,其中各必需氨基酸含量较普通鸡蛋均有不同程度的提高;海洋生命蛋中多不饱和脂肪酸高达30.53%,类胡萝卜素含量达到0.75 mg/枚,而普通鸡蛋仅为0.52 mg/枚;同时,在海洋生命蛋中检测出虾青素,其叶黄素/玉米黄素为1.12,且其有机硒含量为290~490 μg/kg。上述结果表明,添加海洋生物营养强化剂的饲料可较全面地提高鸡蛋的蛋品质。     

Laying hen performance,egg quality improved and yolk 5-methyltetrahydrofolate content increased by dietary supplementation of folic acid

This study was performed to evaluate the effect of folic acid (FA) on performance, egg quality and yolk 5-methyltetrahydrofolate (5-MTHF) content. A total of 384 Hy-line W36 strain hens from 52 to 58 weeks of age were randomly assigned to 4 groups, and each group received one of following dietary treatments: 0, 5, 10 and 15 mg FA/kg diet. A completely randomized design was used. Egg production percentage, egg mass and egg weight were increased significantly (P < 0.05) and feed conversion ratio (FCR) was reduced significantly (P < 0.05) by increasing FA content in diets. No significant differences were detected among treatments on egg quality except for shell thickness. The dietary supplementations of laying hens diets with FA significantly increased yolk 5-MTHF content (P = 0.02). Overall, these data demonstrate that dietary supplementation with FA raised 5-MTHF content of yolk and productivity of egg production in laying hens.     

Effect of the mycotoxin aurofusarin on the antioxidant composition and fatty acid profile of quail eggs.

1. The effect of the mycotoxin aurofusarin on the antioxidant composition and fatty acid profile of quail eggs was investigated. 2. Thirty eight 45-d-old Japanese quails were divided into two groups (experimental and control, 15 females +4 males in each group) and were fed on a maize-soya diet balanced in all nutrients. The diet of the experimental quails was supplemented with aurofusarin at the level of 26.4 mg/kg feed in the form of Fusarium graminearum culture enriched with aurofusarin. At the beginning and after 2, 4 and 8 week supplementation periods, eggs were collected and analysed. After 8 weeks of supplementation, experimental quails were fed on unsupplemented diet during the next 4 weeks and eggs were collected after 2 and 4 weeks on such a diet and analysed. 3. Aurofusarin caused a significant (P<0.05) decrease in vitamins E, A, total carotenoid, lutein and zeaxanthin concentrations and significantly (P<0.05) increased egg yolk susceptibility to lipid peroxidation. During two weeks on the diet without aurofusarin the levels of carotenoids in the egg yolk returned to the initial level, vitamins A and E returned to the initial level during 4 weeks on the same unsupplemented diet. 4. Dietary supplementation with aurofusarin was associated with a significant (P<0.01) decrease in the docosahexaenoic acid proportion in the phospholipid, cholesteryl ester and free fatty acid fractions of the egg yolk. At the same time the proportion of linoleic acid in the phospholipid, free fatty acid and triacylglycerol fractions significantly (P<0.05) increased. 5. It is concluded that mycotoxin aurofusarin is detrimental to the nutritional quality of eggs.     

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.     

七个鸡种蛋品质比较分析

鸡蛋品质是鸡蛋生产者和消费者都非常关注的性状,为分析蛋品质在鸡种内及鸡种间的差异,本试验测定了5个地方鸡种和2个国外蛋鸡品种各30个蛋共12项常规蛋品质指标。分析结果表明:遗传背景对蛋品质影响较大,2个国外鸡种的蛋重、哈氏单位等指标高于地方鸡种,而地方鸡种在蛋形指数、蛋壳质量、蛋黄颜色以及蛋黄比率上占优,国内蛋用鸡种改良可以选择蛋黄性状为重点选育方向。7个鸡种中,海兰白蛋鸡的蛋壳厚度、蛋壳强度、蛋黄重是最大的,但海兰褐蛋鸡却与之完全相反,两者之间差异显著(P<0.05)。从品种内差异角度来看,商业化鸡种蛋品质变异系数小,国内鸡种整齐度有待进一步提高。     

Absence of effects of dietary α‐tocopherol on egg yolk pigmentation

1. Three experiments were carried out in which yolk colour and carotenoid content were measured in hens fed diets containing soyabean oil or tallow and supplemented with 0, 10, 20, 40, 80, 160 or 320 mg tocopheryl acetate.

2. Fat type had no consistent effect on yolk carotenoid content but yolk α‐tocopherol concentrations were lower with the soyabean oil diet.

3. Yolk concentrations of all carotenoids measured and yolk colour were unaffected by dietary α‐tocopherol concentration.     

Alterations in lycopene concentration and Z‐isomer content in egg yolk of hens fed all‐E‐isomer‐rich and Z‐isomer‐rich lycopene

Effects of feeding lycopene isomers to laying hens on egg qualities such as lycopene concentration and color of the yolk were investigated. Firstly, to evaluate the dietary transfer of lycopene to egg yolk, (all‐E)‐lycopene–rich diets (lycopene content, 100, 200, or 300 mg/kg diet) were fed to hens for 21 days. Lycopene in egg yolk could be detected after 4 days or more from the start of feeding, and the lycopene concentration increased according to the feed amount and period. Even though most of the dietary lycopene was the all‐E‐isomer, more than 65% of lycopene in egg yolk was present as Z‐isomers. Thus, the effect of lycopene Z‐isomer content in the diet (lycopene content, 200 mg/kg diet; lycopene Z‐isomer content, 35.1% or 61.3%) on egg qualities was investigated. As the Z‐isomer content increased, the lycopene concentration in the egg yolk increased, for example, when fed a diet rich in Z‐isomers (61.3%), the lycopene concentration in the egg yolk was approximately three times higher than when fed the (all‐E)‐lycopene–rich diet for 21 days. The results indicated that Z‐isomers of lycopene had higher bioavailability and/or higher transfer efficiency to the egg yolk than the all‐E‐isomer.