Is it possible to increase the n-3 fatty acid content of eggs without affecting their technological and/or sensorial quality and the laying performance of hens?

1. The aim of this study was to increase the n-3 fatty acid (n-3 FA) content of eggs without affecting their sensorial and/or technological properties or the laying performance of hens. Laying hens from line 477 were divided into 5 groups corresponding to 5 different diets over the laying period: control diet (C) and diets containing extruded linseed with a high level of fibre (ELHF), extruded linseed with a low level of fibre (ELLF), microalgae, or a combination of 75% ELLF and 25% MA (ELLF+MA).

2. Dietary enrichment with n-3 FA had no effect on the laying performance, hen body weight or egg white viscosity. The egg yolks produced by hens fed the diet containing microalgae were redder than egg yolks from the other groups, suggesting the presence of red pigments in the microalgae preparation. However, the colour difference was low and not perceptible to the human eye. Moreover, colour measurement of egg yolks by sensorial analysis panellists using the Roche colour fan did not reveal a diet effect on this parameter.

3. Egg yolk lipid content was not affected by diet. The egg yolk of hens fed on diets containing linseed and/or microalgae had greater n-3 FA content (×2.5 to 2.9 compared to group C). Linseed mainly increased the linolenic acid content (×3.0 to 3.4 compared to group C) and the microalgae increased the LC n-3 FA content (×4.1 compared to group C). Dietary enrichment with n-3 FA had no effect on the sensorial quality of shell cooked eggs except for the “unusual flavour” criterion for which the score was higher for the MA group compared to the other groups and corresponded to a fishy flavour.

     

Mussel meal as a replacement for fish meal in feeds for organic poultry – a pilot short-term study

Abstract

A trial was performed to evaluate effects of mussel meal in laying hen diets. The study included 96 hens (Lohmann Selected Leghorn). Four diets with 0, 3, 6 or 9% inclusion level of mussel meal, replacing the same quantities of fish meal, were included. At 26 weeks of age, five eggs from each treatment were collected and analysed for internal egg quality. The different contents of mussel meal had no significant effect on production performance or egg quality parameters except from laying percentage and egg yolk pigmentation. Mussel meal concentration up to 6% tended to improve laying percentage compared to the 0% group. Yolk pigmentation increased significantly with increasing levels of mussel meal. There were no differences between the different diets in fatty acid pattern regarding docosahexaenoic acid (DHA), docosapentaenoic acid (DPA) and linolenic acid in the egg yolk. Eicosapentaenoic acid (EPA) decreased significantly when fishmeal was replaced by mussel meal.     

The effects on egg production and egg composition of adding supplements of amino acids and/or urea or dried auto‐claved poultry manure to a low‐protein layer diet

Thirty‐five laying hens of a medium‐weight hybrid strain, aged 10 months, were given a basal diet containing 11.5% protein or the same diet supplemented with 1.54% essential amino acids and/or with two sources of nitrogen for the synthesis of non‐essential amino acids (1.15% urea or 9.7% dried autoclaved poultry manure) for an 8‐week period.

Egg production, food intake, food conversion efficiency, the gross efficiency of nitrogen conversion and the ability of hens to maintain body weight were improved by supplementation with essential amino acids (P < 0.05 or P < 0.01). Supplementation with dried autoclaved poultry manure raised food intake, total egg mass and mean egg weight (P < 0.05), but supplementation with urea alone did not result in significantly higher egg production, perhaps because it failed to increase food intake. Supplementation with essential amino acids and urea to give the equivalent of 16% protein did not result in significantly higher egg production than that obtained with urea alone. The smallest eggs were produced by hens fed on the diet supplemented with urea, and the largest by those fed on the diet supplemented with dried manure (P < 0.001).

The gross composition of eggs was not influenced significantly by dietary treatment but albumen quality was significantly lower on the basal diet and higher on the supplemented diets (P < 0.001). It was highest in eggs from hens fed on the diet supplemented with urea alone.     

Effects of dietary protein on egg production of laying hens housed in furnished or conventional cages

Abstract

In the present experiment the effects of dietary protein content on egg production of hens kept either in conventional cages (CCs) or furnished cages (FCs) were studied. A total of 1088 LSL (Lohmann LSL-Classic Layer) hens were housed in either FCs or CCs and offered high or low protein diets with a protein/energy ratio of 17 or 13, respectively, during three consecutive feeding phases of 20, 16 and 16 weeks, respectively. There was no interaction between the effects of cage design and of dietary treatment on laying performance. Hens kept in FCs consumed less feed than hens in CCs (p<0.05). After the first feeding phase, hens housed in FCs produced fewer eggs (p<0.01) than hens in CCs. No differences in the feed conversion ratio were found between the housing systems. Hens on the low protein diet laid smaller eggs than hens on the high protein diet (p<0.001). No effect of dietary protein on laying rate was found. It can be concluded that dietary protein affects egg production irrespective of the cage type.     

Effects of selected feed additives on the performance of laying hens given a diet rich in maize dried distiller's grains with solubles (DDGS)

1. A total of 192 ISA Brown hens were given diets containing a high concentration of maize dried distiller's grains with solubles (DDGS) and the effect of selected feed additives on laying performance and egg quality was determined.

2. Birds were allocated to 8 treatment groups with 12 replicates (cages) of two hens and were given, from week 26 to 55, iso-caloric and iso-nitrogenous experimental diets with or without a high concentration of DDGS (200 g/kg). The diet containing DDGS was not supplemented or supplemented with enzymes (xylanase and phytase), sodium butyrate, probiotic bacteria (Lactobacillus salivarius) and a mixture of herbal extracts (Taraxaci siccum, Urticae siccum and Salviae siccum), inulin or chitosan.

3. The inclusion of DDGS in the diet had no effect on number of eggs produced, total egg mass, mean egg weight, feed intake or feed conversion ratio. Egg and eggshell quality parameters were also unaffected by dietary DDGS. The yolk colour score (points in Roche scale) was significantly increased by DDGS inclusion. DDGS in the diet caused some changes in the yolk lipid profile that were rather unfavourable from a dietary perspective (an increase of cholesterol content, and PUFA n-6/PUFA n-3 ratio).

4. During the experimental period (26–55 weeks of age) supplementation of the diet containing a high concentration of DDGS with enzymes, inulin as well as chitosan, increased number of eggs produced and daily egg mass. In older hens (50 weeks of age) inulin positively affected eggshell quality parameters, i.e. shell percentage, thickness and density. Diet supplementation with herb extracts, inulin or chitosan, decreased the content of cholesterol in yolks.

5. The results of this study suggest that DDGS may be incorporated up to a concentration of 200 g/kg in the diet of laying hens without any negative effects on egg performance. Moreover, supplementation of xylanase and phytase, as well as inulin and chitosan, can positively affect the performance of layers given diets with a high concentration of DDGS.     

日粮中添加辣诺素对海兰褐蛋鸡产蛋性能和蛋品质的影响

本试验旨在研究日粮中添加辣诺素（辣木和诺丽果的提取物）对蛋鸡生产性能及蛋品质的影响。将产蛋高峰期（22周龄）的海兰褐商品蛋鸡540只随机分为6个处理,每个处理6个重复,每个重复15只鸡。负对照组（NC）饲喂基础日粮,正对照组（PC）饲喂添加50 mg/kg杆菌肽锌的基础日粮,4个试验组分别饲喂添加0.25、0.50、0.75和1.00 g/kg辣诺素（LNS）的基础日粮。试验期24周。结果显示：①日粮处理对蛋鸡试验前期和后期生产性能均无显著影响（P>0.05）,试验后期添加0.50和0.75 g/kg辣诺素有改善料蛋比的趋势（P=0.087）;日粮处理对试验前期和后期鸡蛋蛋形指数、蛋壳强度、蛋壳厚度、蛋黄重和哈氏单位均无显著影响（P>0.05）,但日粮中添加杆菌肽锌和辣诺素有提高蛋壳强度的趋势（P=0.062）,其中以添加0.75g/kg辣诺素组鸡蛋强度最高。②与正、负对照组相比,添加辣诺素显著增加了生蛋黄和熟蛋黄的罗氏蛋黄色比率（P<0.05）,显著降低了蛋黄胆固醇的含量（0.25 LNS组除外）（P<0.05）。③与负对照组相比,添加0.50 g/kg辣诺素显著提高了鸡蛋总黄酮、二十二碳六烯酸（DHA）、卵磷脂、亚麻酸和亚油酸含量（P<0.05）。综合以上试验结果,辣诺素作为饲料添加剂具有提高鸡蛋营养品质的功能,考虑到添加成本,产蛋鸡日粮中添加0.25~0.50 g/kg为宜。     

Long-Term Feeding of Conjugated Linoleic Acid and Fish Oil to Laying Hens: Effects on Hepatic Histopathology,Egg Quality,and Lipid Components

The present study was conducted to investigate the effect of long-term feeding of conjugated linoleic acid (CLA) and fish oil on egg quality characteristics, production performance, liver pathology, and egg fatty acid content of laying hens. Single Comb White Leghorn laying hens (n = 112), 21 wk old, were placed in cages and randomly assigned to 4 diets (28 hens/diet, 4 replicates of 7 hens) containing 3.0% yellow grease (control), 2.75% yellow grease + 0.25% CLA (YG-CLA), 2.5% yellow grease + 0.25% CLA + 0.25% fish oil (YG-CLA-FO), and 2.75% yellow grease + 0.25% fish oil (YG-FO). The experimental diets were fed for 12 mo. Eggs were collected daily for 12 mo. Feed consumption, hen-day egg production, and feed efficiency were monitored. At the end of the trial, hepatic tissue was collected for histopathology. No effect of diet was found on feed consumption, hen-day egg production, feed efficiency, egg weight, yolk weight, shell weight, or Haugh unit. The YG-CLA and YG-CLA-FO diets produced an increase in CLA and saturated fatty acids in the egg and liver tissue with a concomitant reduction in monounsaturated fatty acids (P < 0.05). Feeding YG-CLA-FO and YG-FO increased the n-3 fatty acids in egg yolk and liver of hens (P < 0.05). No difference was observed in the number of fat vacuoles in the liver tissue. The total fat content of hepatic and abdominal fat pads did not differ among treatments (P > 0.05). Regardless of the diet, as the hens aged, egg weight, yolk weight, and egg total fat increased, and shell weight decreased (P < 0.05). These data demonstrate that eggs with increased n-3 fatty acids and CLA can be generated by minor diet modifications without affecting the production performance or health of birds.     

日粮中添加亚麻籽油对鸡蛋脂肪酸组成和风味的影响

试验旨在研究日粮中添加亚麻籽油对蛋鸡生产性能、蛋品质、蛋黄脂肪酸组成及鸡蛋风味的影响。选取40周龄海兰灰商品代蛋鸡288只,随机分为4组,每组8个重复,每个重复9只鸡。设计分别添加0、0.5%、1.0%和3.0%亚麻籽油的4种等能等氮日粮。预试期1周,正试期4周。结果显示：①日粮中添加0.5%、1.0%、3.0%亚麻籽油对产蛋鸡生产性能、蛋品质均无显著影响（P>0.05）;②亚麻籽油可显著提高蛋黄中α-亚麻酸（ALA）、二十碳五烯酸（EPA）、二十二碳六烯酸（DHA）及总n-3多不饱和脂肪酸（PUFA）含量,且其随亚麻籽油添加水平增加呈线性和二次变化（P<0.05）;③3.0%亚麻籽油组显著降低了蛋黄气味及滋味评分,同时显著增强了蛋黄鱼腥气味及滋味评分（P<0.05）,而蛋黄总体接受度显著降低（P<0.05）,且其均随亚麻籽油添加水平增加呈线性和二次变化（P<0.05）;④鸡蛋蛋黄总n-3 PUFA含量与鱼腥气味、滋味间具有显著相关性（P<0.05）,且鸡蛋蛋黄接受度随n-3 PUFA含量增加而降低（R²=0.801）。综上所述,日粮添加亚麻籽油可提高蛋黄总n-3 PUFA含量,但添加量过高时对鸡蛋风味产生不良影响导致总体接受度下降;蛋黄总n-3 PUFA含量不高于21.26 mg/g时,可接受度评分大于5分,鸡蛋感官品质在可接受范围内。     

Effect of dietary supplementation with fermented Ginkgo-leaves on performance,egg quality,lipid metabolism and egg-yolk fatty acids composition in laying hens

The present study was conducted to investigate the effect of 3 types of fermented Ginkgo-leaves (FGL) on layer performance, egg quality, lipid metabolism, microbial populations, and egg-yolk fatty acids composition in laying hens. A total of 432 Lohmann Brown laying hens, 49 weeks of age, were randomly allocated to 4 dietary treatments with 6 replications of 18 birds each. Layers were fed basal diets (Control) or basal diets supplemented with 0.5% Ginkgo-leaves fermented with Candida utilis (CF group), Aspergillus niger (AF group), or their combined fermentation (CAF group), respectively, for an 8-week feeding trial. Compared with the control group, AF and CAF supplementation improved (P<0.05) laying rate and feed conversion ratio. Birds fed FGL (CF, AF and CAF) supplemented diet had a decrease (P<0.05) in cracked-egg rate, egg-yolk cholesterol, serum total cholesterol, triglyceride and low density lipoprotein cholesterol levels, while serum high density lipoprotein cholesterol concentrations of birds from CF and AF groups were increased (P<0.05) compared with that of the control. The concentrations of C18:1 (n-9), C18:2 (n-6), total polyunsaturated fatty acids (PUFA), ratio of PUFA/saturated fatty acids (SFA) and n-6: n-3 was increased (P<0.05 or P<0.01) with FGL supplementation. While FGL supplementation led to a decrease in total saturated fatty acids (P=0.01) concentrations. In addition, ileal and cecum Lactobacilli and Bifidobacteria populations of birds fed FGL were increased (P<0.05) compared with the control group, while ileal Escherichia coli, Salmonellas, and cecal Salmonellas were decreased in birds fed FGL. In conclusion, dietary supplementation of FGL, especially AF and CAF, in layer diets may be a feasible means of producing eggs with lower cholesterol and higher PUFA contents for health conscious consumers.     

Effects of Microbial Phytase Supplementation on Egg Production and Egg Quality in Hy-line Brown Hens During the Late Laying Period

The objective of this study was to evaluate the effects of microbial phytase on egg production and egg quality in older hens. A total of 216, 63-week-old Hy-line brown laying hens were distributed in a randomized complete design 10-week feeding trial of 3 dietary treatments with 12 replications per treatment and 6 hens per replication. The 3 dietary treatments were corn-soybean meal-based diets supplemented with 0% (CON), 0.06% (TRT1), and 0.12% (TRT2) microbial phytase. Significantly higher hen-day egg production was observed in the TRT1 treatment compared to CON (P<0.05), except during the first two weeks of the experiment. During weeks 3, 4, and 9, TRT2 had a greater hen-day egg production percentage than CON (P<0.05). The damaged egg ratio was not affected. The egg quality parameters (e.g., eggshell color, eggshell strength, albumen height, egg weight, and the Haugh unit) were affected by microbial phytase supplementation (P<0.05). However, there were no significant effects on the eggshell thickness and yolk color. In conclusion, microbial phytase supplementation to the diets of older hens could improve production performance, extend the peak laying period, and alter the egg quality parameters.     

Effects of supplementing microalgae in laying hen diets on productive performance,fatty-acid profile,and oxidative stability of eggs

The purpose of this trial was to investigate the effects of adding graded levels of dehydrated, whole-cell microalgae (All-G-Rich^TM, Alltech Inc.) in layer diets on the performance, egg and shell quality, yolk color, oxidative stability, and fatty-acid concentration of eggs. Six replicate groups of 5 Hy-Line W-36 laying hens were assigned to each of 4 dietary treatments. Treatments consisted of feeding a corn-soybean meal control diet alone or supplemented with 1.0, 2.0, or 3.0% All-G-Rich^TM during a 32-wk production period. Fatty-acid content of egg yolk was analyzed after feeding the experimental diets for 4 wk. The docosahexaenoic acid (DHA) content in egg yolk was linearly increased (P < 0.01) with increasing levels of algae in the diet. There was no effect of dietary treatments on production performance of layers in the entire trial period. Egg weight and eggshell quality were not affected by dietary treatments. Supplements of 2 or 3% All-G-Rich^TM significantly increased redness (a*) and decreased lightness (L) of egg yolk. Yolk fatty-acid oxidation, as measured by thiobarbituric acid reactive substances (TBARS), was not affected by treatments in eggs stored up to 30 d at 4°C. Based on these data, adding All-G-Rich^TM in layer diets can produce DHA-enriched eggs with no negative impact on egg quality.     

亚麻籽对鸡蛋中脂肪酸富集及蛋品质的影响

本试验旨在探讨日粮中亚麻籽添加水平和添加时间对蛋中n-3多不饱和脂肪酸的富集以及蛋品质的影响。选取46周龄京粉1号蛋鸡1 344只,随机分为4个组,每组6个重复,每个重复56只。4个处理组日粮中亚麻籽的添加水平分别为0%(对照组)、5%、10%、15%。试验期60 d。试验第10、20、30、45、60天测定蛋中α-亚麻酸、二十碳五烯酸(EPA)、二十二碳六烯酸(DHA)等n-3多不饱和脂肪酸(n-3PUFA)含量。第30、60天测定蛋壳强度、蛋黄色度和哈氏单位。结果表明:亚麻籽的添加水平、时间以及二者互作均对蛋中n-3PUFA的富集产生显著影响,蛋中n-3PUFA含量随着亚麻籽添加水平和添加时间增加呈上升趋势,随后达到稳定;5%亚麻籽组中鸡蛋DHA含量最高,其他脂肪酸含量以15%亚麻籽组最高;蛋中EPA含量在20 d达到最高,其他脂肪酸在30 d达到最高;蛋黄色度随着日粮中亚麻籽添加水平升高而显著降低,其他蛋品质指标无显著变化。由此表明,给蛋鸡饲喂含15%亚麻籽日粮30 d以上,可获得理想n-3PUFA富集鸡蛋,但要保证日粮色素水平稳定。     

Evaluation of pearl millet and flaxseed effects on egg production and n-3 fatty acid content

1. A 6-week trial was conducted to evaluate the effects of pearl millet (PM) as a replacement for maize, in combination with flaxseed (FS), on productivity, egg trait parameters and egg n-3 fatty acid (FA) content in White Leghorn hens. 2. Six diet treatments were used: a control (CTL, maize-soybean meal based) diet, and diets containing 0, 2, 4, 8 or 12% FS, in which all maize was replaced by PM (PM-0, PM-2, PM-4, PM-8 and PM-12, respectively). All diets were isocaloric and isonitrogenous and met NRC (1994) requirements. Eight cage replicates per treatment were used (three hens per cage). At the end of each week, three eggs were randomly collected from each cage to measure egg trait parameters and yolks were separated, pooled and lyophilised for FA determination. Body weights and feed consumption were recorded weekly. Egg production (number of eggs and egg mass produced) was recorded daily. At the end of the experiment, all hens were killed to determine liver haemorrhage score. 3. Egg traits and flock performance parameters were not different among treatments except at week 4, when birds on the PM-12 diet produced smaller eggs than hens on the PM-0 and PM-2 diets. Yolk pigmentation scores were lower for the PM-0 and PM-2 diets (1.60 +/- 0.24 and 1.80 +/- 0.20, respectively), increased with higher inclusions of FS (2.75 +/- 0.47 for PM-12 diet) but did not reach control levels (6.00 +/- 0.01). Liver haemorrhage scores were not affected by dietary treatment. Hens given the PM-8 and PM-12 diets produced eggs with n-3 FA content higher than required to be considered as n-3 FA enriched eggs, and had a lower n-6/n-3 FA acid ratio than eggs of hens consuming CTL or the PM based diets with lower FS supplementation. 4. These results suggest that PM can be used to substitute for maize in the diets of layers and may reduce the amount of FS needed to obtain n-3 FA enriched eggs.     

Sweet white Lupinus Albus (cv buttercup) as a feedstuff for layers

1. An experiment was conducted with laying hens to determine to what extent sweet white lupins (Lupinus albus, cv Buttercup) could be used as a protein source in their diets.

2. Twenty five individually caged 20 week‐old Hisex laying hens were used per treatment. The hens were housed in a convection house for the duration of the study which lasted 52 weeks. Two diets were formulated, one containing 300 g sweet lupins/kg and the other containing sunflower oil cake and fish meal as protein sources. These diets were blended to obtain seven diets with lupin inclusion rates of 0, 50, 100, 150, 200, 250 and 300 g/k.

3. Results indicated that up to 300 g lupins/kg diet can be fed to Hisex laying hens without a significant effect on egg production, egg mass, efficiency of food utilisation, egg shell thickness, Haugh units or yolk colour. Food intake was however, significantly (P<0.05) positively correlated with lupin inclusion rates.     

The influence of dietary boron supplementation on egg quality and serum calcium, inorganic phosphorus, magnesium levels and alkaline phosphatase activity in laying hens

This study was performed to investigate the influence of dietary boron (B) supplementation on egg production, interior and exterior egg quality and serum parameters related to egg formation in laying hens. Two hundred and twenty four, 18 week old, Hyline Brown 98 strain hens were assigned to 7 groups with 4 replicates. After 10 days of adaptation the hens were fed for 8 weeks on diets supplemented with 0, 5, 10, 50, 100, 200 and 400 mg/kg (diet) B (H₃BO₃). Live weight, feed consumption and egg production were reduced in the 400 mg/kg B supplemented group. Increases were determined in serum Ca, inorganic P and Mg levels and serum ALP activity was not influenced by supplemental B. Boron changed the interior and exterior quality of eggs. In particular, high level of B supplementation reduced live weight, feed consumption and egg production and changed some blood metabolites.     

苜蓿皂苷对蛋鸡生产性能和蛋品质的影响

本文以460日龄的褐壳蛋鸡为试验对象,在蛋鸡饲粮中添加不同水平紫花苜蓿皂苷,研究其对蛋鸡生产性能和蛋品质的影响。试验将200只蛋鸡随机分为5个处理,分别饲喂基础日粮(Ⅰ),基础日粮+0.5%胆固醇(Ⅱ),基础日粮+0.5%胆固醇+120 mg·kg^-1苜蓿皂苷(Ⅲ),基础日粮+0.5%胆固醇+240 mg·kg^-1苜蓿皂苷(Ⅳ),基础日粮+0.5%胆固醇+480 mg·kg^-1苜蓿皂苷(Ⅴ),试验期为63 d。结果表明:在蛋鸡饲粮中添加胆固醇或胆固醇+不同水平的苜蓿皂苷均能改善其产蛋率、增加蛋重、降低料蛋比,其中0.5%胆固醇+120 mg·kg^-1组效果显著。添加胆固醇对蛋黄重改进作用较大;各试验组的蛋黄颜色都有改进,其中0.5%胆固醇+240 mg·kg^-1苜蓿皂苷组(Ⅳ)和0.5%胆固醇+480 mg·kg^-1苜蓿皂苷组(Ⅴ)的蛋黄颜色显著提高;各试验组的哈氏单位都较对照组高,其中0.5%胆固醇+480 mg·kg^-1组(Ⅴ)提高显著。综合认为,在蛋鸡饲粮中添加胆固醇或胆固醇+苜蓿皂苷有提高蛋鸡生产性能和蛋品质的作用。     

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.     

Effects of Chinese herbal mixture on performance,egg quality and blood biochemical parameters of laying hens

The aim of the study was to evaluate the effect of Chinese herbal mixture (CHM) in laying hen diets on performance, egg quality and egg nutrition components, as well as selected blood biochemical parameters. A total of 270 Lohmann Brown laying hens, 24 week of age, were randomly distributed into three dietary treatments and fed for 6 week. The CHM was used at the levels of 0%, 0.5% and 1.0% in the diets of the control and two treatment groups respectively. Each dietary treatment was divided into five replicates, comprising of 18 hens each. Hens were housed in a 3‐tier battery system. Feed and water were provided ad libitum. Blood samples and eggs were collected at the end of the experiment. The results showed that dietary treatments did not affect egg weight, mortality, eggshell thickness, albumen height, Haugh units, eggshell‐breaking strength and egg‐shape index. Dietary supplementation of CHM significantly improved (p < 0.05) laying rate and the lowest feed conversion ratio were observed with 1.0% CHM supplementation diets. CHM supplementation decreased (p < 0.05) cracked‐egg rate, egg yolk cholesterol, blood serum levels of cholesterol, triglyceride, low‐density lipoprotein cholesterol (LDL‐C) and alanine aminotransferase (ALT) and increased blood serum levels of high‐density lipoprotein cholesterol (HDL‐C). No differences in serum total protein, serum albumen, serum glucose and aspartate amino transferase (AST) were observed in hens fed CHM. In conclusion, dietary supplementation with CHM improved egg production and egg quality and reduced serum cholesterol concentrations in laying hens. Dietary supplementation of 1.0% CHM in layer diets may be a feasible means of producing eggs with lower cholesterol and higher egg yolk phospholipid contents for health conscious consumers.     

Effects of zinc oxide nanoparticles on the egg quality,immune response,zinc retention,and blood parameters of laying hens in the late phase of production

The objective of this study was to evaluate the effects of dietary supplementation with zinc oxide nanoparticles (ZnO‐NPs) on the performance, egg quality, Zn retention, immunity responses, superoxide dismutase activity (SOD), egg malondialdehyde (MDA) content, and serum parameters in laying hens in the late phase of production. A total of 288 laying hens at 64 weeks of age were randomly assigned to 4 treatments with 6 replicates, and 12 birds within each group. Experimental diets included a corn‐soybean meal‐based diet (without Zn supplementation) and a basal diet supplemented with 80 mg/kg of Zn‐oxide, ZnO‐NPs, and Zn‐methionine. The results indicated that egg production and egg mass were significantly higher in the Zn‐methionine and ZnO‐NPs groups (p < .05). Also, eggshell thickness and shell strength increased in the ZnO‐NPs group as compared with the other groups (p < .05). Moreover, Zn supplementation decreased egg loss (p < .05). There were significant differences among treatments in Zn deposition in tibiotarsus, liver, pancreas, eggs, and excreta (p < .01). Antibody titre, heterophil (%(, and phytohemagglutinin (PHA) were significantly higher in birds fed with Zn‐supplemented diets (p < .05). In treatments supplemented with ZnO‐NPs and Zn‐methionine, the SOD activity in the liver, pancreas, and plasma was greater as compared with the other treatments (p < .05). The MDA content in eggs was significantly reduced in groups supplemented with Zn (p < .01). Moreover, dietary Zn supplementation significantly affected serum total protein, albumin, glucose, alkaline phosphatase activity, carbonic anhydrase activity, and Zn level (p < .05). In conclusion, this study demonstrated that dietary supplementation with ZnO‐NPs can improve the performance of laying hens. Therefore, ZnO‐NPs can enhance zinc absorption in the intestine of aged layers and can be a more suitable source of zinc than regular Zn‐oxide in diets.     

Direct supplementation of diet is the most efficient way of enriching broiler meat with n-3 long-chain polyunsaturated fatty acids

1. Concentrations of beneficial omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFAs) in poultry meat can be improved by increasing the concentration of n-3 PUFA in poultry diets.

2. A decrease in flavour quality is, however, usually associated with the dietary supplementation with n-3 PUFA, which is due to the susceptibility of PUFA to oxidation.

3. This experiment was conducted to study the effects of introducing two different n-3 fatty acid sources (extruded linseed and DHA Gold?, a proprietary algal product rich in docosahexaenoic acid), either separately or together, on broiler productive performance, and meat quality, oxidative stability, sensory traits and LC-PUFA profile.

4. Birds given the algal product displayed better productive performances than animals from other groups.

5. The data revealed an improvement in the fatty acid nutritional value of meat from birds receiving the algal product and an inefficient conversion of α-linolenic acid (LNA) into LC-PUFA.

6. Metabolisation of LNA in vivo is not sufficient to improve meat quality in n-3 LC-PUFA and direct supplementation of the diet with n-3 LC-PUFA is a better alternative to modulate an increase in beneficial fatty acids of broiler meat.

7. The overall acceptability of meat was negatively affected by the dietary supplementation with 7.4% of DHA, in contrast to the supplementation with 3.7% of DHA, which showed to be efficient in improving LC-PUFA meat content without affecting its sensory properties.