Yolk Color Research Articles

Use of Herbal Feed Additives to Enhance Meat and Yolk Color in Poultry

Diese Arbeit zeigt die Verwendung von pflanzlichen Futtermittelzusätzen zur Verbesserung der Fleisch- und Dotterfarbe bei Geflügel, wobei der Schwerpunkt auf in Indien durchgeführten Studien liegt. Der wachsende Wunsch nach natürlichen und sicheren Hühnerprodukten hat Forscher dazu veranlasst, sich mit alternativen Futtermittelzusatzstoffen zu befassen, insbesondere mit pflanzlichen, die in Indien aufgrund der reichen biologischen Vielfalt und der Traditionen der Kräutermedizin reichlich vorhanden sind. Der Artikel fasst die Ergebnisse mehrerer indischer Studien zusammen und konzentriert sich dabei auf wesentliche pflanzliche Zusatzstoffe wie Kurkuma, Paprika, Ringelblume usw. Der Artikel untersucht, wie diese Chemikalien die Farbe beeinflussen, die zugrundeliegenden Mechanismen, den potenziellen Nutzen und die Grenzen sowie künftige Forschungsmöglichkeiten in Indien. Die indische Forschung bietet einzigartige Einblicke in die Vorteile pflanzlicher Futtermittelzusatzstoffe, die zum weltweiten Trend einer natürlichen und nachhaltigen Geflügelproduktion beitragen. Dieser Artikel unterstreicht das Potenzial von pflanzlichen Zusätzen zur Verbesserung der Qualität von Geflügelprodukten und zur Erfüllung der Kundennachfrage nach natürlichen, gesundheitsfördernden Lebensmitteln.

Inclusion of Lutein and Zeaxanthin in Standard or Omega-3 Fatty Acids Enriched Laying Hens Diets: Effects on Performance, Egg Quality Parameters, Fatty Acid Composition and Individual Carotenoids Concentration of Egg Yolk

The effects of lutein (L) and zeaxanthin (Z) inclusion to standard or omega-3 fatty acids enriched laying hens’ diets, on performance, egg quality parameters, fatty acids and individual carotenoids of egg yolk was investigated. The dietary treatments were designed as: standard (S) diet, 50 mg/kg L plus 50 mg/kg Z (S+L/Z (50+50)) or 100 mg/kg lutein plus 100 mg/kg zeaxanthin (S+L/Z (100+100)) added to S diet, Omega-3 fatty acids enriched (OM3) diet, 50 mg/kg lutein plus 50 mg/kg zeaxanthin (OM3+L/Z (50+50) or 100 mg/kg lutein plus 100 mg/kg zeaxanthin (OM3+L/Z (100+100)) added to OM3 diet. Hens with a mean live weight of 1525.88 ± 31.19 g were divided into six treatment groups. During the experimental period, there was not any mortality rate recorded. Dietary inclusion of L/Z (50+50 or 100+100) either in S or OM3 diets did not alter performance parameters. Eggs from hens fed enriched diet (OM3) significantly increased (P<0.05) the albumen index and Haugh unit. The type of dietary fat source (F), equal dose of L/Z or F×L/Z on egg yolk lutein, unknown carotenoids and total carotenoid concentration were found to be significant. However, the F on zeaxanthin concentration was not significant (P>0.05). The yolk color a* value was significantly increased by inclusion of L/Z (50+50 or 100+100) to diets (S or OM3) (P<0.05) and this was correlated with increased (P<0.05) concentration of individual carotenoids. The major changes in egg yolk fatty acid MUFA and PUFA composition occurred when laying hen fed with OM3 diet. Key words: Egg yolk, omega-3, carotenoids, lutein, zeaxanth

Assessment of performance and egg quality in laying hens of Spanish indigenous breed Black Castellana as compared with a selected white egg-layer strain

Indigenous animal genetic resources should be preserved because of their well adaptation to the environment, their tolerance to low food availability and their sociocultural importance. The characterization of the quality of the products generated by heritage breeds may bring more arguments to encourage the raising of these animals. This study aimed at evaluating the egg performance and quality of Spanish indigenous Black Castellana (BC) breed as compared with a selected strain (Lohmann LSL-Classic). Four groups of 30 hens were arranged: 1) Lohmann hens fed a control diet; 2) BC hens fed the control diet; 3) Lohmann hens fed a diet including linseed at 70 g/kg (omega-3 diet); 4) BC hens fed the omega-3 diet. Egg production was higher by 12.3% for Lohmann hens but, since BC eggs were heavier by 15.4%, no effect of genetics was found on daily egg mass. Feed intake was higher by 5.0% for BC hens. Nonetheless, no difference was detected for feed conversion ratio. Eggshell was thicker by 6.78% in Lohmann eggs. Haugh units did not differ among freshly laid and stored eggs in Lohmann hens, whereas Haugh units decreased in stored BC eggs (80.5 vs. 76.7 vs. 72.3 at 0, 14, and 30 d of storage). Yolks of BC eggs contained less fat (57.5 vs. 60.8% DM), more protein (32.8 vs. 31.9% DM) and more cholecalciferol (1.25 vs. 1.22 μg/g DM), and showed lower proportion of saturated fatty acids (29.0 vs. 37.0%) and higher proportions of monounsaturated (45.7 vs. 39.6%) and polyunsaturated (25.2 vs. 23.4%) fatty acids. Feeding the omega-3 diet reduced the yolk proportions of saturated (32.5 vs. 33.5%) and monounsaturated (42.0 vs. 43.3%) fatty acids and increased those of polyunsaturated (25.4 vs. 23.2%) and ω-3 (7.05 vs. 2.42%) fatty acids. No effect due to genetics or diet was found on yolk color score or on yolk content in cholesterol, cobalamin, retinol and γ-tocopherol. This study represents the first exhaustive characterization of eggs from Spanish indigenous Black Castellana breed.

Effect of Feeding Unpeeled Cassava Mash as Substitute for Maize in Layers Diet on Egg Quality and Hematological Parameters

The effect of feeding unpeeled cassava mash on layers to evaluate egg quality and hematological indices was investigated with one hundred and fifty birds that were thirty-four weeks old which were randomly allotted to five dietary treatments of 30 birds and replicated twice with fifteen birds each. The experiment lasted for 10 weeks in a Completely Randomized Design (CRD). Treatment 1 (100% maize) serves as control, while treatments 2, 3, 4 and 5 were 25% unpeeled cassava mash, 50% unpeeled cassava mash, 100% unpeeled cassava mash and 25% peeled cassava mash respectively. There was significant (P<0.05) difference in shell surface area, Egg length, Egg breadth, Egg shape index, shell thickness and yolk colour score in all the treatments, while other parameters measured were not significantly different. As for Heamatological indices. There was no significant difference in all parameters measured. Haemoglobin (Hb) increased slightly with increased levels of unpeeled cassava mash inclusion. In conclusion replacement of unpeeled maize up to 100% inclusion level has no deleterious effect on the birds but the best result that can compete favourably with maize is 50% inclusion level. Therefore 50% inclusion level is recommended to farmers to maximize production and achieve desired result.

Factors Influencing the Effects of Triticale on Laying Hens’ Performance: A Meta-Analysis

Multiple studies have yielded conflicting findings regarding the impact of incorporating triticale as a feed ingredient on laying hens’ production parameters. This article used a meta-analysis to assess the factors influencing its effects on layers’ performance. According to the PRISMA guidelines, articles examining the influence of triticale on layers’ egg production (EP), egg weight (EW), egg yolk color (EYC), feed intake (FI), and feed conversion ratio (FCR) were identified across Google Scholar, PubMed, and Science Direct. As a result, six articles were selected and categorized into 16 experiments for inclusion in our meta-analysis. Overall, the trim-and-fill method indicated that triticale had comparable effects to conventional cereals on the performance of laying hens. However, the meta-ANOVA emphasized that the Hy-Line Brown hen strain and Joesong and Juanilo triticale strains induced the best laying hen performance. Moreover, the meta-regression emphasized a positive correlation between the triticale inclusion percentage and the EW in Juanilo triticale diets and a negative correlation between the triticale inclusion percentages and the EYC in the triticale and laying hens strains studied. Therefore, this meta-analysis makes a valuable contribution to comprehending the factors that may influence the effects of triticale on the performance of layers.

Effects of full-fat high-oleic soybean meal in layer diets on performance, egg quality and chemical composition

The utilization of full-fat high-oleic soybean meal in layer diets could lead to value-added poultry products. To test this idea, 336 hens were randomly assigned to 4 isonitrogenous (18.5% CP) and isocaloric (2,927 kcal/kg) formulated diets and fed the following diets for eight weeks: conventional control solvent-extracted defatted soybean meal (CON); extruded-expelled defatted soybean meal (EENO); full fat normal-oleic soybean meal (FFNO); or full fat high-oleic soybean meal (FFHO). Body weights (BW) were collected at week 0 and week 8. Eggs were collected daily, and the totals counted each week. Feed consumption was measured weekly, and egg quality was measured bi-weekly. Eggs were collected at wk 0 and wk 8 for fatty acid analysis. There were no significant treatment differences in any of the production parameters measured, BW, feed consumption, feed conversion ratio or egg production (P > 0.05). Eggshell strength was significantly greater in eggs produced from the EENO group as compared to the control (P < 0.01), while egg yolk color was significantly darker in eggs of the control and EENO treatment groups relative to the FFNO and FFHO treatments (P < 0.0001). Eggs produced by hens fed the FFHO diet had a 52% increase in monounsaturated n-9 oleic acid content (P < 0.0001) and reduced palmitic (P < 0.01) and stearic (P < 0.0001) saturated fatty acid levels as compared to the conventional controls. These results validate the utilization of FFHO as a value-added poultry feed ingredient to enrich the eggs and/or poultry meat produced.

Effects of chlorogenic acid on productive and reproductive performances, egg quality, antioxidant functions, and intestinal microenvironment in aged breeder laying hens

This study investigated the effects of dietary chlorogenic acid (CGA) on the productive and reproductive performance, egg quality, antioxidant function, and intestinal microenvironment of laying hens. Thus, 162 healthy Hy-Line Brown breeding hens (63 weeks old) were randomly allocated to 3 groups, each receiving a basal diet plus supplementation: 0, 250, and 500 mg/kg CGA, respectively. Per the in vitro test, CGA had obvious inhibitory effects on Salmonella enteritis and avian pathogenic Escherichia coli and strong free radical scavenging ability. Per the breeder laying hen experiment, the CGA diets had no significant influence on egg production or reproductive performance (P < 0.05). Nevertheless, compared with the control diet, 250 mg/kg CGA significantly increased eggshell thickness, egg weight, yolk color, and Haugh unit (P < 0.05). Compared with the control diet and 500 mg/kg CGA, 250 mg/kg CGA significantly (P < 0.05) elevated antioxidant capacity by reducing serum malondialdehyde content, upregulating heme oxygenase-1, and downregulating heat shock proteins mRNA levels in the ileum. Compared with the control diet and 500 mg/kg CGA, 250 mg/kg CGA (P < 0.05) enhanced intestinal barrier function, shown by the upregulation of ileal Occludin and Mucin-2 mRNA levels; furthermore, 250 mg/kg CGA (P < 0.05) increased anti-apoptotic capacity by increasing B-cell leukemia/lymphoma 2 gene expression and downregulated Bcl2 Associated X mRNA levels in the liver and ileum of late breeder laying hens (P < 0.05). Lastly, 250 mg/kg CGA (P < 0.05) increased cecal g_CHKCI001 and short-chain fatty acid-producing bacteria g_Prevotellaceae UCG-001, positively related to gut health, and in the cecum, 500 mg/kg CGA significantly (P < 0.05) increased g_Shuttleworthia abundance, negatively related to gut health. Our findings suggest that dietary inclusion of 250 mg/kg CGA promotes egg quality, intestinal microbial composition, gut barrier integrity, and the antioxidant capacity of aged breeder laying hens.

Supplementation of a Calcium-fish oil mixture in the diet on egg quality in Lohmann Brown laying hens

The aim of this study was to examine the impact of dietary calcium-fish oil (Ca-fish oil) mixture supplementation on egg quality in Lohmann Brown laying hens aged 45-53 weeks. This study used 160 Lohmann Brown laying hens aged 53 which were randomized into 4 types of treatment and 4 replications and each replication used 40 hens with homogeneous body weights. The four treatments were levels of shellfish meal in fish oil, namely 0%, 1.2%, 2.2% and 3.2% for treatments P0, P1, P2, and P3, respectively. The results showed that supplementation of a mixture of shellfish flour with fish oil significantly (P&lt;0.05) could increase egg weight, egg yolk color, egg white weight, egg yolk weight, eggshell weight, eggshell thickness, eggshell color, pH and haugh unit. But, significantly different (P&lt;0.05) reduced fat and cholesterol levels in yolk. Meanwhile, the egg index and egg protein content were not significantly different (P&gt;0.05). Based on the research results, it can be concluded that supplementation of a Calcium-fish oil mixture in feed at the level of 1.2-3.2% is able to improve the physical and chemical quality of eggs, and can reduce fat and cholesterol levels in yolk in Lohman Brown laying hens.

The Effects of Different Doses of Canthaxanthin in the Diet of Laying Hens on Egg Quality, Physical Characteristics, Metabolic Mechanism, and Offspring Health.

Currently, there is a dearth of in-depth analysis and research on the impact of canthaxanthin on the production performance, egg quality, physical characteristics, and offspring health of laying hens. Furthermore, the metabolic mechanism of cantharidin in the body remains unclear. Therefore, to solve the above issues in detail, our study was conducted with a control group (C group), a low-dose canthaxanthin group (L group), and a high-dose canthaxanthin group (H group), each fed for a period of 40 days. Production performance was monitored during the experiment, in which L and H groups showed a significant increase in ADFI. Eggs were collected for quality analysis, revealing no significant differences in qualities except for yolk color (YC). The YC of the C group almost did not change, ranging from 6.08 to 6.20; however, the trend in YC change in other groups showed an initial intense increase, followed by a decrease, and eventually reached dynamic equilibrium. By detecting the content of canthaxanthin in the yolk, the YC change trend was found to be correlated with canthaxanthin levels in the yolk. The content of unsaturated fatty acid increased slightly in L and H groups. Following the incubation period, the physical characteristics and blood biochemical indices of chicks were evaluated. It was observed that the shank color of chicks in the L and H groups was significantly higher than that in the C group at birth. However, by the 35th day, there were no significant differences in shank color among the three groups. Further investigation into the metabolic mechanism involving canthaxanthin revealed that the substance underwent incomplete metabolism upon entering the body, resulting in its accumulation as well as metabolic by-product accumulation in the yolk. In summary, this study highlighted the importance of understanding canthaxanthin's role in production performance, egg quality, and offspring health, providing valuable insights for breeders to optimize feeding strategies.

Effects of micelle silymarin in corn-soybean meal-based diet on laying hens' performance, egg quality, and blood profile, with comparative assessment of blood absorption rates between powdered and micelle silymarin

Micelle silymarin (MS) is recognized for its diverse range of beneficial properties, which encompass anti-inflammatory, antioxidant, hepatoprotective, and antidiabetic effects. The main objective of this study was to examine the effects of micelle silymarin on the performance, egg quality, blood profile, and absorption rate of silymarin in laying hens. In experiment 1: 288 Hy-Line brown laying hens, 28 wk old, were utilized for this experiment. The hens were randomly allocated into 3 dietary treatment groups, with each group comprising eight replicates of 12 hens, each housed in individual pens with access to feed and water. Over a 12-wk feeding trial, the hens were provided with a basal diet supplemented with different levels of MS: 0, 0.03, and 0.06%. In experiment 2: For this experiment, 192 Hy-Line Brown laying hens were divided into 2 dietary treatment groups, with each group comprising eight replications of 12 hens. The dietary treatments were: TRT1, basal diet + powder silymarin 4%; TRT2, basal diet + MS 4%. From the first experiment, the findings revealed that incorporating micelle silymarin (MS) into the hens' diet significantly increased egg weight at wk 6 (P < 0.05). Similarly, at wk 12 and throughout the entire experiment, significant effects were observed on downgraded egg count, egg production, egg weight, and feed conversion ratio (FCR) (P < 0.05). Moreover, Haugh Units (HU) and albumen height showed a linear improvement (P < 0.05) at wk 4 with MS supplementation. Furthermore, there was a linear increase in egg yolk color, albumen height, and eggshell thickness at wk 8 with MS supplementation (P < 0.05). Furthermore, a layers-fed diet supplemented with MS showed a linear increase (P < 0.05) in HU, egg weight, yolk color, albumen height, eggshell strength, and eggshell thickness in wk 12. Regarding blood profile parameters, the study revealed linear reductions for aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) (P < 0.05), whereas there was a tendency for albumin, triglyceride, and cholesterol (P < 0.10). In the second experiment, it was observed that the blood absorption rate of silymarin was higher in TRT2 compared to TRT1 at 2- and 4-h intervals following administration. In summary, increasing MS supplementation in the diet of laying hens enhanced egg production, egg quality, and blood profile. Additionally, silymarin absorption was higher in its micelle form than in its powder form.

The change of albumen quality during the laying cycle and its potential physiological and molecular basis of laying hens

To elucidate the regulatory mechanisms that impact variability in albumen quality of laying hens from the peak of lay to the late production phase. A 60-week study was conducted on a cohort of 20,000 Hy-Line Brown laying hens from 20 to 80 weeks old. Before commencement at 20 weeks, the 10-week-old hens were acclimatized for ten weeks. This study examined changes in albumen quality, serum, and liver antioxidant capacity, magnum morphology, and expression of albumen-protein-related genes in the magnum. To reduce sampling error, we collected eggs (n=90) from pre-determined cages at every sampling point (5-week intervals), and 8 hens were selected at 10-week intervals for blood and tissue collection. Our findings revealed that age significantly affected most evaluated parameters. Albumen gel properties, including hardness, gumminess, and chewiness, increased significantly with age (P < 0.05). With the increasing of hens' age from 20 to 80 weeks, the albumen proportion of eggs was decreased, but eggshell proportion, yolk proportion, thick albumen proportion, thick to thin ratio, thick albumen solid content, albumen height, Haugh units, and yolk color were increased and then decreased (P < 0.05). Compared to hens aged 20-60 weeks, the hens (70-80 weeks) had significantly reduced total antioxidant capacity (TAC) and glutathione levels (GSH) in the liver and lower serum TAC and superoxide dismutase levels (SOD) (P < 0.05). The magnum mucosal folds were highest in 40-60 weeks-old hens, and the luminal diameter increased with age (P < 0.05). In the magnum, the mRNA expression levels for OVA, CPE, and NUP205 increased significantly between 30 and 40 weeks, while FBN1 expression was higher between 30 and 50 weeks (P < 0.05). At 70-80 weeks, the expression of BRCA2 was significantly downregulated (P < 0.05). Albumen height, thick albumen proportion with protein secretion-related genes, enhanced antioxidant function, and luminal diameter correlated positively. However, the thick-to-thin albumen ratio negatively correlated with BRCA2, downregulated in aged laying hens. We used principal component and cluster analysis to deduce albumen quality changes during three phases: 25-35, 40-55, and 60-80 weeks. The decline in albumen quality in aging hens is linked with decreased antioxidant capacity, magnum health, and downregulation of key genes involved in protein synthesis and secretion. These findings emphasize critical albumen quality changes in laying hens and suggest molecular pathways underlying age-related albumen quality alterations.

Effects of Inclusion of Mango Peel Waste in Diets of Layer Chickens on Performance and Egg Quality in Kenya

Alternative ingredients for the manufacture of poultry feeds need to be identified to meet the growing demand. A 42-day feeding trial was conducted to investigate the effects of the inclusion of mango peel waste in layer chicken diets on performance and egg quality. This study involved one hundred and fifty Isa Brown layer chickens aged 60 weeks. These chickens were assigned to five treatments with graded levels of mango peels: 0% (Treatment 1), 3.5% (Treatment 2), 7% (Treatment 3), 14% (Treatment 4) and 28% (Treatment 5), using a completely randomized design (CRD). Daily egg production was recorded, and weekly measurements included feed intake, specific gravity, egg weight, shell weight and shell thickness. Notably, Treatment 5 exhibited the highest feed conversion ratio (3.09) and Roche yolk color (RYC) fan score (14.3), which was significantly (p &lt; 0.05) different from Treatment 1, with values of 2.36 and 12.4, respectively. Layer chicken fed on T1 had the highest egg weight and egg thickness (6.6 g and 0.44 mm, respectively), differing significantly (p &lt; 0.05) from Treatment T5 eggs (6.3 g and 0.41 mm). It was concluded that mango peels could substitute maize in layer chicken diets up to 7% without affecting production and egg quality. Mango peels are recommended for partial substitution of maize in layer chicken diets and as natural egg yolk pigment to impart the yellow yolk desired by consumers.

Dietary Aronia melanocarpa supplementation inhibit the oxidative stress caused by aging in ovary of late laying hens from 59 to 67 weeks of age

The ageing of laying hens’ ovaries in the late laying period leads to oxidative stress, which ultimately results in the decrease of laying performance. Thus, we investigated Aronia melanocarpa (AM) as a potent antioxidant to improve ovarian senescence in the late laying hens through antioxidant pathway, thereby improving egg production performance. A total of 480 Hy-line brown laying hens aged 59 wks (60–67 wks) were randomly divided into CON, LAM, MAM and HAM groups and fed 0, 1, 4 and 7% AM, respectively. The results showed that compared with the CON group, the MAM group could significantly improve the laying rate and reduce the feed egg ratio at 64–67 weeks of age (p < 0.05). The AM groups increased the eggshell thickness, while HAM group significantly reduced yolk colour (p < 0.05). The MAM and HAM groups significantly increased egg white weight (p < 0.05). Meanwhile, the ovarian index in MAM group was increased, and the proteins related to proliferation and anti-apoptosis of ovarian cells (PCNA and Bcl2/Bax) were enhanced in all AM groups (p < 0.05). Compared with the CON group, all AM groups could significantly reduce the malondialdehyde (MDA) content of ovary and yolk, and increase the activities of glutathione peroxidase (GSH-Px) and total superoxide dismutase (T-SOD) in yolk. LAM and MAM groups significantly increased ovarian GSH-Px activity, but only the MAM group significantly increased ovarian T-SOD activity. The expression levels of Nuclear factor E2-related factor 2 (Nrf2), haem oxygenase 1 (HO-1) and glutathione peroxidase 1 (GPX1) genes and proteins were significantly increased in all AM groups, while the expression levels of kelch ECH – associated protein 1 (Keap1) genes and proteins were decreased. The expressions of NAD(P)H: quinone oxidoreductase 1 (NQO1) and superoxide dismutase 1 (SOD1) genes were significantly increased in all AM groups, but the expression of SOD1 protein was significantly increased in MAM group and NQO1 protein was significantly increased in HAM group. Antioxidant enzyme protein expressions in the ovary showed positive associations with antioxidant enzyme activity. Furthermore, the expression of Nrf2 protein in the ovary was inversely connected with Keap1 protein expression and favourably correlated with antioxidant protein expressions. In summary, dietary AM supplementation activates the Keap1/Nrf2 antioxidant pathway to inhibit the oxidative stress caused by ageing in ovary of late laying hens. Taken together, the results of the study suggest that the inclusion of 4% AM was able to better improve the laying performance and antioxidant capacity of laying hens in the late laying period.

Impact of Moringa oleifera Leaf Meal on Egg Quality Traits in Japanese quail

To evaluate the effect of diet supplementation with Moringa oleifera leaf meal (MOLM) on egg quality traits of Japanese quails, a study was conducted for 16 weeks. For this purpose, a total of 270 adult female quails and 90 adult male quails of seven weeks of age were divided into 5 groups (M0, M0.5, M1, M1.5, and M2) of 3 replicates of 24 birds (18 females and 6 males) each. The groups corresponded to 0, 0.5, 1, 1.5, and 2% inclusion levels of MOLM. The egg quality traits were studied fortnightly in four randomly collected eggs per replicate. An improvement (P≤0.05) in the egg quality traits, particularly egg shape index, albumen index, yolk colour score, and Haugh unit was recorded in the quails fed MOLM-based diets which denote better egg quality and higher chances of acceptability of the eggs by the consumer. It is concluded that MOLM can be safely included at 2% in the diets of Japanese quails.

Exploring the effects of varying levels of selenium-chitosan on production performance, egg quality, and immune health in laying japanese quail

The purpose of this research was to see how different levels of Se-chitosan, a novel organic source of Se, affected the production performance, egg quality, egg Se concentration, microbial population, immunological response, antioxidant status, and yolk fatty acid profile of laying Japanese quail. This experiment used a totally randomized design, with 5 treatments, 6 repeats, and 10 birds in each repetition. The dietary treatment groups were as follows: no Se supplementation (control group), 0.2 mg/kg Na-selenite supplementation, and 0.2, 0.4, and 0.6 mg/kg Se-chitosan supplementation. The feed conversion ratio (FCR) improved linearly in quails fed different levels of Se-chitosan compared to the control group (P < 0.05). Furthermore, Se-chitosan at concentrations of 0.2 and 0.4 mg/kg demonstrated both linear and quadratic increases in albumen height, Haugh unit, and yolk color in fresh eggs compared to the control group. Additionally, Se-chitosan contributed to enhanced shell thickness and strength, along with an increased Se concentration in the yolk. Se-chitosan supplementation at different levels linearly and quadratically reduced coliforms (COL) while increasing lactic acid bacteria (LAB)/coliform ratios (P < 0.05). Se-chitosan supplementation linearly and quadratically increased the total antibody response to sheep red blood cells (SRBC) and IgG titers (P < 0.05). It also linearly decreased the level of malondialdehyde in fresh and stored egg yolks and increased the activity of antioxidant enzymes catalase and glutathione peroxidase linearly, and superoxide dismutase (SOD) both linearly and quadratically in quail blood serum (P < 0.05). Additionally, supplementation of Se-chitosan at levels of 0.2 and 0.6 mg/kg linearly decreased the ∑ n-6 PUFA/∑ n-3 PUFA ratio in the yolk compared to the control group (P < 0.05). It can be concluded that incorporating Se-chitosan as a novel organic source of Se in the diet of laying quails can enhance production performance, egg quality, egg Se concentration, yolk lipid oxidation, microbial population, immune response, antioxidant enzyme activity, and yolk fatty acid profile.

Analysis of the Quality and Chemical Composition of Double-Yolked Eggs Compared to Those of a Normal Structure.

The study material consisted of 360 eggs from a reproductive flock of meat-type hens; 240 were double-yolked eggs and 120 were single-yolked as a control group. The eggs were numbered individually and then analysed for their quality in terms of characteristics of the whole egg (weight, shape index, specific gravity), shell (colour, strength, weight, density), albumen (pH, height, weight, Haugh units) and yolk (colour, weight, shape index, pH). During the analyses, yolks were sampled for analyses including basic composition, fatty acid profile (by gas chromatography) and fatty acid indices. It was found that double-yolked eggs differed significantly from single-yolked ones in terms of weight, proportion of individual elements in the egg weight, total protein content in the yolks as well as in terms of the fatty acid profile and their indices both due to the presence or absence of two yolks and in the context of the individual yolks analysed. The results indicate the possibility of using double-yolked eggs as table eggs due to the absence of negative effects stemming from being double-yolked and the increased content of biologically important components such as fatty acids.

The effects of different plant extract supplementation into drinking water egg laying performance and egg quality in second production cycle

This study aimed to investigate the effects of different plant extract supplementation into drinking water egg laying performance and egg quality parameters in second production cycle under commercial conditions. A total of 16657 Nick Brown laying hens in a second production cycle, kept in free-range system, used in the experiment between 75-83 weeks of age. The experimental groups were consisted of three treatment: CONT - control group (no supplementation), PEXT1 - combination of artichoke (Cynara scolymus) and turmeric (Curcuma longa) supplementation, PEXT2 – combination of cinnamon (Cinnamomum venum) + echinacea (Echinacea purpurea) + turmeric (Curcuma longa) supplementation as liquid form into drinking water. The supplementation was performed twice on weekly basis with an amount of 1 l / ton drinking water. The mean value of hen-housed and hen-day egg production, and egg weight were interestingly increased in the control group, than the PEXT1 and PEXT2 groups. However, a more efficient of FCR was found for the PEXT2 group. The breaking strength was found to be the highest in the eggs of PEXT1, whereas a higher value for shell thickness was observed in PEXT1 and PEXT2 groups. Egg yolk had a darker tone in the PEXT1 and PEXT2 groups. According to the results of the present study, it could be concluded that using a combination of cinnamon, echinacea and turmeric could improve feed efficiency. Furthermore, supplementation of plant extracts enhanced the egg quality, namely shell strength and yolk color, during the second cycle of egg production.

Enriching Eggs with Bioactive Compounds through the Inclusion of Grape Pomace in Laying Hens Diet: Effect on Internal and External Egg Quality Parameters.

(1) Background: Grapes and their associated by-products (such as grape pomace, GP) stand out for their polyphenol content, which makes them a source of bioactive compounds with antioxidant capacity. The aim of this research was to determine if the inclusion of 50 g/kg of GP in the diet of hens could enrich eggs with antioxidants and to study its effect on internal and external egg quality parameters. (2) Methods: A trial was conducted with two genetic lines of hens, which were fed either a control diet or a diet containing 50 g/kg of GP. Performance, internal and external egg quality, and egg yolk content of vitamins E and A and gallic acid were determined. (3) Results: In eggs laid by hens fed a GP diet, Haugh units and yolk color scores were enhanced, and eggshells became thinner, but without affecting the breaking strength. No dietary effect was observed on the vitamin contents of the yolk. A higher gallic acid content was observed in the yolks of eggs laid by hens fed the GP diet, suggesting that some dietary phenolic compounds could be transferred to the eggs. Hen genetics influenced egg weight, albumen Haugh units, shell thickness, and α- and γ-tocopherol concentration in yolks. (4) Conclusions: Dietary inclusion of GP improved the internal quality of eggs, enriching yolks with a phenolic compound but reducing shell thickness.

Decontamination of egg‐associated pathogens by plasma‐activated water and hydrogen peroxide

AbstractThis study investigated the effectiveness of plasma‐activated water (PAW) and plasma‐activated hydrogen peroxide (PAHP) in reducing egg‐associated pathogens. The antimicrobial activity of these solutions against Salmonella Enteritidis, Campylobacter jejuni, and Staphylococcus aureus on eggs was evaluated at different plasma treatment durations. The results demonstrated that increasing the duration of plasma treatment enhanced the antimicrobial efficacy of both PAW and PAHP. The bacterial counts of the egg‐associated pathogens significantly decreased from 7.61, 7.59, and 7.54 log (CFU/egg) to 5.4 and 3.09, 5.36 and 3.11, and 5.08 and 3.73 log (CFU/egg) for PAW and PAHP, respectively. The characteristics of the plasma solutions, including electrical conductivity, pH, H2O2, NO3¯, and NO2¯, synergistically acted as antimicrobial agents in both PAW and PAHP treatments. The storage study revealed that PAHP treatment had no adverse effects on the eggs' pH, albumen and yolk color, Haugh unit, and yolk index. However, it did result in reduced eggshell strength and compromised cuticle integrity. Overall, this study demonstrates the successful application of PAW and PAHP in effectively inhibiting egg‐associated pathogens while preserving essential egg quality attributes. Further research is needed to optimize the treatment conditions and investigate the long‐term effects of PAW and PAHP on eggs in larger‐scale applications. This research contributes to developing innovative and sustainable approaches for enhancing the safety and quality of eggs in the food industry.

Performance and egg quality traits of local chickens across different agroecologies in the Kewot district, North Shewa zone, Northern Ethiopia

This study was conducted to evaluate the performance (productive and reproductive) potential and egg quality traits of local chickens (LCs) across different agroecologies (AEs) in the Kewot district, North Shewa zone, northern Ethiopia. A multistage sampling technique was used to select the study sites and households (HHs). The data were collected through semi-structured questionnaires, monitoring and measurements. A total of 147 HHs were included in this study. Ninety brooding hens were monitored to determine hatchability and survivability percentages. A body weight of 120 LCs was measured at the market centres. Furthermore, the egg quality traits of 120 freshly laid eggs were evaluated. The data were analysed by a statistical package for social sciences (version 20). In the study area, the average flock size of the LC/HH populations was 9.90 ± 0.36. The most common flock type was chicks, followed by pullets, with significantly lower (p < 0.05) in the lowland (LL) AE. The mean age at first egg of females and the mean age at sexual maturity of males were 6.05 ± 0.06 and 5.68 ± 0.08 months, respectively. The numbers of eggs per clutch and per year were 14.29 ± 0.40 and 50.02 ± 1.51, respectively. There was no significant difference (p > 0.05) in the average number of clutches/hen/year across AEs, while significantly lower (p < 0.05) numbers of eggs per clutch and per year were recorded for highland (HL) AEs than for LL agro-ecology. The mean hatchability percentage was 80.94 ± 1.69%. The mean market body weights of the male and female LCs were 0.91 ± 0.05 and 0.82 ± 0.05 kg, respectively. There were significant differences (p < 0.05) in egg weight, egg width, shell thickness, shell ratio, albumen height, albumen and yolk weight, yolk colour, and Haugh unit (HU) between the AEs. The results revealed that the performance potential and egg quality traits of the LC in the study district were somewhat poor. Therefore, AE-specific development interventions should be designed and implemented to improve the performance potential and egg quality traits of LC in the study area.